The Evaluation Of Lower Extremity Arterial Occlusive Disease Of Diabetic Patients With 64-slice CT Angiography

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.