【作者】 温泽迎；

【导师】 张小安； 葛英辉；

【作者基本信息】 郑州大学 ， 影像医学与核医学， 2010， 硕士

【摘要】 目的探讨64层CT血管成像在诊断糖尿病下肢动脉硬化闭塞症中的影像学价值。材料与方法对33例糖尿病下肢血管病变患者的40条下肢分别行64层螺旋CT血管成像(64-CTA)及数字减影血管造影(DSA)。每条下肢动脉分为12个节段,分别为肾下腹主动脉、髂总动脉、髂外动脉、髂内动脉、股浅动脉、股深动脉、胭动脉、胫前动脉、胫后动脉、腓动脉、足背动脉和足底内动脉,共计218个节段。以DSA为标准,对12个节段动脉进行对比分析。结果CTA与DSA对照,在膝以上动脉中(肾下腹主动脉、髂总动脉、髂外动脉、髂内动脉、股浅动脉、股深动脉和胭动脉),共有163个血管节段行DSA和CTA的比较,CTA诊断的敏感性、特异性、阳性预测值、阴性预测值及诊断符合率分别为100%、75.9%、79.4%、100%和86.4%。在膝以下动脉中(胫前动脉、胫后动脉、腓动脉、足背动脉和足底内动脉),共有55个血管节段行DSA和CTA的比较,CTA诊断的敏感性、特异性、阳性预测值、阴性预测值及诊断符合率分别为91.7%、75.9%、91.7%、80%及89.1%。结论64层CTA对糖尿病下肢动脉硬化闭塞症有较高的诊断价值,在一定程度上可以代替DSA作为糖尿病下肢动脉硬化闭塞症的常规检查方法。目的采用64层CT血管成像(CTA)探讨糖尿病患者下肢动脉硬化闭塞症的病变特点。材料与方法62例临床诊断下肢动脉硬化闭塞症的患者按照有无糖尿病合并症分为糖尿病组(DM)及非糖尿病组(NDM),分别为33例和29例,使用64层螺旋CT行下肢动脉CTA检查,采用动脉造影的12分段积分法将下肢动脉分为12个节段,分析各个血管节段的斑块分布情况(斑块检出率)及斑块性质,分别对各个节段的管腔狭窄程度进行对比分析。结果在膝以上大动脉(包括胭动脉及其以上血管)病变中,两组血管的斑块检出率未见统计学差异(P>0.05),且均以混合斑块为主；动脉病变狭窄程度积分DM组为L:6.51±3.47,R:6.96±3.08；NDM组为L:4.86±2.06,R:5.34±2.02。两组未见统计学差异(P>0.05)。膝以下小动脉(包括胫前动脉发出点及其以下血管)病变中,DM组的斑块检出率明显高于NDM组(P<0.05),且主要以硬斑为主,后者则以少量软斑为主；病变狭窄程度积分,DM组为L:7.96±3.10,R:8.30±2.48；NDM组为L:3.27±1.66,R:3.34±1.42,两组有统计学差异(P<0.05)。结论糖尿病患者并发下肢动脉硬化性闭塞症较单纯高血压患者严重,以膝下终末血管受累较为明显,且以弥漫性硬斑为主。目的探讨64层螺旋CT自动毫安技术及低千伏技术对降低下肢动脉血管成像辐射剂量的可行性。材料与方法82例糖尿病下肢动脉闭塞症患者,随机分为三组,分别采用不同的扫描技术。第一组(group 1, n=26)采用120KV的常规电压,固定毫安技术；第二组(group 2, n=26)采用120KV的自动毫安技术(650mA)；第三组(group 3, n=30)采用80KV的自动毫安技术(650-30mA),噪声指数NI=10。扫描范围肾下腹主动脉至足尖,分别选择骨盆平面、胭窝层面平面、小腿中下段平面及足底平面作为观察平面,对三种扫描技术的图像质量、图像噪声和辐射剂量进行统计学分析。结果自肾下腹主动脉至足底容积的扫描长度为105.57-123.43cm,三组平均扫描长度分别为118.52±6.91cm,113.39±5.55cm,106.39±7.59cm,差异无统计学意义(P>0.05)。三组的辐射剂量CTDIvol分别为14.48±3.60,5.56±2.16,2.99±0.73mGy；平均DLP分别为1703.54±347.7,679.6±267.3及360.95±91.47 mGycm,三组间差异有明显统计学意义(t1,2=11.62,t2,34.58,P值均<0.05),第二、三组较第一组辐射剂量分别平均降低约60.10%和78.81%。第一组的四个选取平面图像噪声分别为11.89±2.73、6.63±1.24、7.50±1.74及5.95±1.84；第二组的图像噪声分别为14.73±2.30、12.24±2.62、11.92±2.40及11.38±3.24,第三组的图像噪声分别为20.57±2.86、15.06±3.28、14.77±3.63及12.40±2.35。第二组图像噪声均高于第一组,组间差异有统计学意义(t1,2值分别为3.69、8.57、6.72及6.49,P)值均<0.05,)。第三组与第二组比较,在骨盆层面、胭窝层面和小腿层面图像噪声均较第二组高(t2,3=8.10,3.43,3.30,P值<0.05)。足底层面的两组图像噪声差异无统计学意义(t2,3=1.33,P值>0.05)。三组图像质量的评分分别为2.57±0.50、2.26±0.48、2.56±0.56,差异无统计学意义(t1,2=0.57,t2,3=0.67,P值>0.05)。结论在其他扫描参数不变及保证图像质量的情况下,采用120kV和80kV的自动毫安技术均能更有效的降低病人辐射剂量,以80kV效果更明显。更多还原

【Abstract】 ObjectiveThe aim of this study was to determine the concordance between CT angiography (CTA) and digital subtraction angiography (DSA) in diabetic patients with lower extremity arterial occlusive disease (LAOD).Material and MethodsThirty-three patients underwent both CTA and DSA. The artery of lower extremity was divided into 12 anatomic segments, then to analysis the stenosis of the artery, and to evaluate the sensitivity and specificity of CTA with DSA.ResultsIn total,218 segments were assessed by both CTA and DSA. In the artery above the knee including infrarenal aorta, common iliac artery, external iliac artery, internal iliac artery, superficial artery, deep femoral artery and popliteal artery, the sensitivity and specificity of CTA were 100% and 75.9% respectively. For the artery below the kneel, including anterior artery, posterior artery, peroneal artery, plantar artery and dorsal artery of foot, the sensitivity and specificity of CTA were 91.7%and 75.9% respectively. Conclusions64-slice CTA provides a more valuable way for the detection of diabetic patients with peripheral arterial occlusive disease.ObjectiveTo evaluate the lower extremity arterial occlusive disease of diabetic patients with 64-slice CTMaterial and Methods62 patients diagnosed lower extremity arterial occlusive disease were divided into two groups(DM group and HP group) according to whether having diabetes, including 33 diabetic patients and 29 hypertensive patients, and all these patients underwent 64-slice CT angiography. The artery of lower extremity was divided into 12 anatomic segments which were scored on the basis of vessel lumen stenosis, then to analysis the distribution and the quality of the plaque in every segment of the artery, and to compare the severity of the artery between two groups.ResultsIn the artery above the knee(from the infrarenal aorta to and including the popliteal artery), there is no significant difference about vessel stenosis between DM(5.39±5.07) and HP group(5.37±4.51), (P>0.05), and the differences of the detection of plaques were not apparent as well as the quality of plaques(P>0.05). However, In the artery below the knee (from the start of anterior tibial artery to dorsal artery of foot), patients with DM(4.00±3.75) tended to have a higher score than that with HP(1.96±2.48), (P<0.05), and the detection ratio of plaques in DM group which were mainly with calcified plaques was much higher than that in HP group which were mainly with soft plaques (P<0.05).ConclusionsThe lower limb atherosclerosis in DM group is much severe than in HP group, especially in distal segments of the artery below the knee, where the hard plaques in DM group takes the largest proportion.ObjectiveMinimizing radiation dose for lower extremity arterial scanning is necessary due to the long scan range. The purpose of this study was to determine whether comparable results to the standard 120kVp protocol could be obtained with reduced radiation dose for lower extremity arterial imaging by 64-slice CT at a tube voltage of 80 kVp. Material and MethodsEighty-two consecutive diabetic outpatients with lower extremity occlusive disease were randomly divided into three groups. They were scanned with a 64-slices CT scanner by using different scanning techniques. The first group (group 1, n=26) used standard 120kVp and fixed tube current of 180mAs (group 1), and the second (group 2, n=26) and third groups (group 3, n=30) used 120kVp and 80kVp with automatic tube current modulation, respectively. We selected the observing levels at pelvic, knee, calf and foot levels for noise measurement and image quality assessment with a 3-point scale. Paired analyses were performed on radiation dose, image quality, and image noise using t-test.ResultsThe scan lengths for all three groups were statistically the same (P>0.05). The CTDIvol and DLP values for the three groups were (14.48±3.60,5.56±2.16 and 2.99±0.73mGy) and (1703.54±347.7,679.6±267.3 and 360.95±91.47mGycm). Radiation dose was reduced by 60% and 79% for group2 and group3, respectively compared to group 1, and was statistically significant (tCTDIvo1=10.63, tDLP= 11.62, P<0.05 for group1 and group2), and( tCTDIvo1=4.57, tDLP=4.58,P<0.05 for group 1 and group 3). At the foot level, there was no significant difference for image noise between group 2 and group 3 (P>0.05), but at the other three levels, group 3 had higher image noise than group 2 (P<0.05). Group 2 also had higher noise than group 1 (P<0.05). However, there was no significant difference in image quality scores (2.57±0.50,2.26±0.48 and 2.56±0.56) between the three groups (t1,2=0.57, t2,3= 0.67, P>0.05).ConclusionUsing automatic tube current modulation for lower extremity arterial scanning can reduce radiation dose. Radiation dose can further be reduced with equivalent image quality by using 80 kVp.更多还原