Yue Dong, Presenter: Nothing to Disclose

Yijun Liu, Abstract Co-Author: Nothing to Disclose

Ruxin Wang, Abstract Co-Author: Nothing to Disclose

Lifei Sun ARRT, MBBS, Abstract Co-Author: Nothing to Disclose

Renwang Pu MBBCh, FRCPC, Abstract Co-Author: Nothing to Disclose

Liang Hu, Abstract Co-Author: Nothing to Disclose

To investigate low dose and low contrast medium volume CT angiography and to compare the image quality and diagnostic accuracy at different doses with digital subtraction angiography (DSA) in the evaluation of the abdominal aorta and lower extremity vessels. 

31 patients with a clinical diagnosis of obstructive arterial disease of the extremities underwent MDCT (GE Discovery 750HD) angiography of the aorta and peripheral vessels. Group A:21 patients, 120kVp, noise index of 7,150ml of contrast medium 350 at 5ml/s. Group B:10 patients, 80kVp, noise index of 15, 80ml of contrast medium 350 at 3ml/s followed by 40ml saline flush. Two protocols used auto mA mode and AISR 30% reconstruction. The measurement of radiation dose was based on the CTDI and DLP. Image quality was analyzed by two vascular radiologists in consensus using a three-point scale(poor, better and good). The arterial system was divided into 19 anatomical segments (from abdominal aorta to ankle arteries). Each segment was evaluated for patency by using a five point scale: 1=normal, 2=moderate disease (<50% stenosis), 3=single severe stenosis (>50% stenosis), 4=diffuse severe stenosis (>50% stenosis) and 5=complete occlusion. DSA represented the reference.

Mean CTDI and DLP of group B (6.8±1.7mGy, 926.26±172.21mGy•cm) were reduced by 66.7% and 62.8%, compared with group A(20.4±3.6mGy, 2489.42±362.48mGy•cm). The average overall diagnostic image quality for the 2 groups was graded as good or better. No difference in image quality was seen between group A and B(p>0.05). Group A revealed a sensitivity, specificity, accuracy,PPV and NPV of 96%, 96%, 96%, 89% and 99% in the evaluation of the presence and degree of stenosis compared to 93%, 92%, 94%, 84% and 97% for Group B.

Low dose scan with low contrast medium volume was a feasible option for the abdominal aorta and lower extremity vessels angiography. This technique provides less contrast medium and lower radiation exposure to the patient while maintaining optimal diagnostic accuracy.

For the abdominal aorta and lower extremity vessels angiography,This technique provides less contrast medium and lower radiation exposure to the patient while maintaining optimal diagnostic accuracy.

Dong, Y, Liu, Y, Wang, R, Sun, L, Pu, R, Hu, L, Low Dose and Low Contrast Medium Volume CT Angiography of the Abdominal Aorta and Lower Extremity Vessels.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045590.html