| BackgroundLower extremity vascular disease is a common complication of type 2 diabetes.It is important for diabetic foot in patients with type 2 diabetes to prevent and treat by accurate examination and diagnosis early,Traditional diagnosis of lower extremity vascular disease mainly by DSA and color Doppler ultrasound,DSA could give dynamic information of vascular morphology,high sensitivity to small vessel disease,but it is an invasive examination,as a two dimensional inspection,the effect is limited.Ultrasound as a noninvasive examination,the method is simple,cheap,but this method is subject to the operator’s proficiency,probe pressure,sound beam direction and other factors,the lack of reliability and accuracy of the inspection results.At present,,CT angiography has been fully affirmed in the diagnosis of vascular patches and luminal stenosis degree of lower extremity vascular with the development of multi slice spiral CT,software update and technology.ObjectiveTo investigate and evaluate the feasibility of 64 slice spiral CT with low voltage,low dose and low dose of contrast agent in the lower extremity of patients with type 2 diabetes.Methods142 cases of diabetic foot in patients received the treatment were choose as studying object on September 2013 and 2015 December in our hospital,the 90 cases were male,52 cases were female,old age 4278,mean age（61.7 ± 8.2）,foot disease 0.528 months.Average（11.6 ± 4.7）months.All patients were randomly divided into 4 groups,19 cases of the routine group（120KV,370mgI/ml contrast agent,1.5m L/Kg）,low voltage with low dose group（41 cases）,low voltage with low concentration group（41 cases）and low voltage with low dose and low concentration group（41 cases）,the low voltage with low dose group was divided into the experimental A1 group（21 cases,100 KV,370mgI/ml contrast agent,1.5m L/Kg）and experimental A2 group（20 cases,100 KV,370mgI/ml contrast agent,0.8m L/Kg）.Low voltage with low concentration groupwas divided into experimental B1 group（21 cases,100 KV,300mgI/ml contrast agent,1.5mL/Kg）and experimental B2 group（20 cases,80 KV,300mgI/ml contrast agent,1.5m L/Kg）according to the experimental.Low voltage with low dose and low concentration group was divided into experimental C1group（21 cases,100 KV,300mgI/ml contrast agent,1m L/Kg,BMI≥25 Kg/cm2）and experimental C2 group（20 cases,80 KV,300mgI/ml contrast agent,0.8m L/Kg,BMI<25 Kg/cm2）.lower limb of the patients in Routine group,Low voltage with low dose and low concentration group received CTA examination within a week,lower limb vascular of 52 volunteer of 142 patients received DSA examination.Two independment senior attending physicians with vascular imaging diagnostic experience in interpreting CTA based 3 points: 1.the subjective image quality score and objective image quality was analysised 4,on the basis of test results,narrow degree of lower extremity artery was recorded,and the amount of contrast agent,DLP and ED was calculated.Using statistical software to analyze the data,P≤0.05 for the difference was statistically significant.Results1 the effect of low voltage and low dose on image qualityOriginal axial image score was 3.72±0.31,3.69±0.39,3.74±0.33,VR image score was 3.78± 0.25,3.79 ± 0.22,3.80±0.22 and MIP images score was 3.83±0.21,3.85±0.25,3.86±0.22 in each group（Routine group,experimental A1,experimental A2）.the difference was not statistically significant between Routine group,experimental A1,experimental A2（P > 0.05）.CT number had no significant difference among three groups（P>0.05）.Background noise experiment in A2 group（33.28±4.12）Hu was significantly higher than the experimental A1 group（29.47±3.46）Hu,the experimental A1 group was significantly higher than the conventional group（18.93±2.64）Hu（P≤0.05）.Signal-noise ratio and contrast-to-noise ratio was increased with noise decreased,which experimental A2 group（10.53±1.75,8.63±1.28）was significantly lower than that of experiment group A1（13.87±2.29,1.146±2.11）,the experimental A1 group was significantly lower than that of the conventional group（18.99±3.17,15.91±281）.The difference was statistically significance（P≤0.05）.2 the effect of low voltage and low concentration on image qualityOriginal axial image score was 3.72±0.31、3.71±0.36、3.74±0.377,VR image score was 3.78±0.25,3.80±0.23,3.82±0.24 and MIP images score was 3.85±0.21,3.86±0.19,3.87±0.23 in each group（Routine group,experimental B1,experimental B2）.the difference was not statistically significant between Routine group,experimental B1,experimental B2（P > 0.05）.CT number had no significant difference among three groups（P>0.05）.Background noise experiment in B2 group（28.55±4.26）Hu was significantly higher than the experimental B1group（23.88±3.53）Hu,the experimental B1 group was significantly higher than the conventional group（18.93±2.64）Hu（P ≤0.05）.Signal-noise ratio and contrast-to-noise ratio was increased with noise decreased,which experimental B2 group（12.21±1.48、9.99±1.27）was significantly lower than that of experiment group B1（14.71±2.18 、 12.14±2.261）,the experimental B1 group was significantly lower than that of the conventional group（18.99±3.17 、 18.99±3.17 、15.91±2.81）.The difference was statistically significance（P≤0.05）.3 the effect of low voltage with low dose and low concentration on image qualityOriginal axial image score was 0.72±0.31,3.74±0.38,3.75±0.35,VR image score was 3.78±0.25,3.81±0.24,3.83±0.25 and MIP images score was 3.83±0.21,3.87±0.21,3.89±0.24 in each group（Routine group,experimental C1,experimental C2）.the difference was not statistically significant between routine group,experimental C1,experimental C2（P > 0.05）.CT number had no significant difference among three groups（P>0.05）...Background noise in experiment C2 group（27.51±4.22）Hu was significantly higher than the experimental C1group（22.47±3.57）Hu,the experimental C1 group was significantly higher than the conventional group（18.93±2.64）Hu（P≤0.05）.Signal-noise ratio and contrast-to-noise ratio was increased with noise decreased,which experimental C2 group（12.59±1.71,10.21±1.25）was significantly lower than that of experiment group C1（14.71±2.18,12.14±2.261）,the experimental C1 group was significantly lower than that of the conventional group（15.59±2.22,12.74±2.09）.The difference was statistically significance（P≤0.05）.4 the effect of low voltage with low dose and low concentration on radiation doseCTD IVOL was（10.51±0.00）mGy,（847±0.00）mGy,（648 ±0.00）mGy,DLP was（1025.43 ±63.59）mGy.cm,（875.48± 57.83）mGy.cm,（639.28±43.47）mGy.cm,and Ed was（19.37±0.78）mSv,（16.37±0.71）m Sv,（11.28±0.47）mSv] in each group（Routine group,experimental C1,experimental C2）,CTD IVOL DLP,ED in the experimental C2 group was significantly lower that in the experimental C1 group,CTD IVOL DLP,ED in the experimental C1 group significantly lower than that routine group,The difference was statistically significance（P≤0.05）.5 Comparison of low tube voltage,low dose,low concentration of CTA and DSA in the assessment of lower extremity vascular stenosisIn the present study,the CTA was found to show that the degree of stenosis of 256 segment was consistent with DSA in the conventional group,and the accuracy was 95.17%.CTA overestimated 10（3.72%）,underestimate the 3（1.12%）.The Kappa value is 0.947,which suggests that the two methods are in good agreement..The luminal stenosis of moderate and above as the overall analysis,the sensitivity and specificity of CTA were 93.7% and 95%,positive predictive value and negative predictive value were 93.5% and 93.9%.In the present study,the CTA was found to show that the degree of stenosis of 250 segment was consistent with DSA in in the experimental C1 group,and the accuracy was 95.78%.CTA overestimated 7（2.68%）,underestimate the 4（1.53%）.The Kappa value is 0.954,which suggests that the two methods are in good agreement.,The luminal stenosis of moderate and above as the overall analysis,the sensitivity and specificity of CTA i were 94.2% and 96.3%,positive predictive value and negative predictive value were 95% and 95.5%.In the present study,the CTA was found to show that the degree of stenosis of 250 segment was consistent with DSA in in the experimental C2 group,and the accuracy was 94.7%.CTA overestimated 5（1.89%）,underestimate the 6（2.27%）.The Kappa value is 0.947,which suggests that the two methods are in good agreement.,,The luminal stenosis of moderate and above as the overall analysis,the sensitivity and specificity of CTA i were 94.1% and 95.5%,positive predictive value and negative predictive value were 94.1% and 95.5%.Conclusion1.CTA examination of the lower in patients with type II diabetes mellitus based low tube voltage with low dose and low concentration contrast can ensure the quality of the image and reduce the radiation dose to patients.2.CTA examination of the lower in patients with type II diabetes mellitus based low tube voltage with low dose and low concentration contrast can meet the requirements of clinical diagnosis,and reduce the concentration and total amount of contrast to reduce the occurrence of contrast nephropathy effectively to.3.CTA examination of luminal stenosis degree of lower extremity vascular of the lower in patients with type II diabetes mellitus based low tube voltage with low dose and low concentration contrast agree with DSA,and can be used as a clinical diagnostic and follow-up of patients with type 2diabetes lower extremity. |
PDF Full Text Request