| Objectives: To compare Multiple Planar Reconstruction(MPR) with Virtual Intravascular Endoscopy's(VIE) in detection of stenosis ratio of coronary artery and explore VIE's value in diagnosing coronary artery remodeling and in-stent restenosis.Materials and methods:1. Patients without stents group: A total of 56 patients who were diagnosed of coronary arteries remodeling were collected. They were all examined by CT and verified by DSA. All of these cases were had coronary arteries reconstruction images scores. The scores were higher than 4 were studied. Base on the result of the scores, 62 sections of coronary arteries were studied.Patients with stents group: A total of 12 patients who underwent MDCT scanning after 6 to 18 months of stents implanted. They were all verified by DSA in 1 week. All of these cases were had stents reconstruction images scores. The scoreswere higher than 2 were studied. Base on the result of the scores, 22 stents were studied.2. MSCT scans were performed with a 64-slice scanner (Toshiba Aquilion ) with the following protocols: Images were acquired with 64×0.5mm slice collimation, tube energy of 120 kv and an effective tube current of 280 mAs, pitch 0.2-0.26, reconstruction interval of 0.4mm. They had calcification score scan first. For the contrast-enhanced scan, Non ionic Contrast medium (iopamiro 370 or ioversol 320, 60–80ml) was injected onto the antecubital vein at 5ml/s for the first 40–60ml, and 3.5ml/s for the remaining 20ml followed by 50ml of saline chasing at 5ml/s, and the scan was performed with a bolus tracking technique with a CT attenuation of 180-220HU as the triggering threshold at the descending aorta to initiate the scan. Volume data were reconstructed at 70–80% R-R interval to minimize the artifacts. For patients with a heart rate more than 70 bpm, a beta-blocker was used to slow down the heart rate.3. All acquired data were transferred and analyzed in Toshiba workstation (Vitrea 4.0), such as VR,MIP,MPR,CPR,SSD,VIE. One radiologist was responsible for reconstructing images.4. SCA scans were performed with Philips Allura 12 digital subtraction angiography. SCA were completed by the physician of cardiology, who didn't know the result of MSCTA before.5. Statistical methods: Independent-Samples T test was used to analyze measurement data. Chi-Square test andκcoefficient test were used to analyze enumeration data(α=0.05,p<0.05,respectively). In addition, the relationship among common influencing factors and stenosis ratio was studied.Results:Patients without stents group:1. The stenosis ratio was statistically different between MPR and VIE. VIE had higher coincidence to DSA(ΚVIE>κMPR,p<0.05);The accuracy to diagnose coronary arteries remodeling was statistically different between MPR and VIE(χ2=6.84>χ2(0.05),p<0.05);2. The stenosis ratio of MPR correlated positively with Calcification Score (r=0.449,p<0.05). The Calcification Score didn't have significant influence on the stenosis ratio of VIE (p>0.05);Patients with stents group:1. The accuracy to diagnose in-stent restenosis was statistically different between MPR and VIE. VIE had higher coincidence to DSA(ΚVIE>κMPR,p<0.05);2. The stenosis ratio of MPR was positively correlated with Calcification Score (r=0.86,p<0.05).The Calcification Score didn't have significant influence on the stenosis ratio of VIE (p>0.05).The stenosis ratio of MPR correlated positively with the length of stent (r=0.29, p<0.05). The length of stent didn't have significant influence on the stenosis ratio of VIE (p>0.05).Conclusions:VIE has higher clinical value in evaluating coronary artery's remodeling than MPR. It can cut down the effect of patients'high Calcification Score, motion constructed defect. It has advancement to observe the Lumen of blood vessel. In patients with stents group, VIE can cut down the effect of patients'high Calcification Score, metal constructed defect of stents and the length of stents. VIE can observe the Lumen of the stent and raise the accuracy of diagnosing in-stent restenosis.
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