Abstract:It is difficult for conventional computed tomography（computed tomography，CT） to assess vascular disease caused by head and carotid artery stenosis，occlusion，etc.，failing to show vascular variation，malformation，narrow degree，collateral circulation and plaque characteristics. Computed tomography angiography（CT angiography，CTA） is a non-invasive imaging technology for rapid e－valuation of the head and neck vascular system. This paper first summarizes the correlation between CTA and anatomy and segmenta－tion basis of head and neck vessels. Then，based on the advantage of CTA in screening the anatomy and morphology of the head and neck vascular system，the application referring to the diagnosis of common cerebrovascular diseases，the progress of new technologies and the corresponding advantages and limitations has been reviewed. Finally，the future development direction of CTA is prospected.

Abstract:This expert consensus comes from the international society of cardiovascular CT（SCCT），which provides the basis for CT diagnosis and risk stratification of coronary artery disease in women. Among women without cardiovascular disease symptoms，coronary artery calcification was associated with a greater than 7.5% risk of atherosclerotic cardiovascular disease within 10 years. CT angiog－raphy（CTA） can not only accurately detect obstructive coronary artery disease（CAD），but also identify the scope and composition of non-obstructive atherosclerotic plaque.

Abstract:Objective：To evaluate the reliability of advanced vascular analysis（AVA） software and volume computed tomography digital subtraction angiography（VCTDSA） for bone subtraction on computed tomography angiography（CTA） of the normal head and neck. Methods：The imaging data of normal head and neck CTA for 30 subjects in the First Affiliated Hospital of Chongqing Medical University were retrospectively analyzed. The same operator used AVA software and VCTDSA for bone-subtraction in the original images，recorded the time of automatic subtraction，manual subtraction，and total subtraction，and evaluated the VR and MIP images in the aspects of vascular integrity，image quality，and false vascular stenosis. The Mann-Whitney U test was used to compare the subtraction time，the paired chi-square test was used to evaluate vascular integrity，and the rank sum test for dependent samples was used to evaluate image quality and false vascular stenosis. Results：The time of automatic subtraction，manual subtraction，and total subtraction of VCTDSA was 14.5（13，20.25） seconds，399（353.75，501.75） seconds，and 415.5（371.5，516） seconds，respectively，while that of AVA was 116.5（109，123.25） seconds，11.5（0，71.25） seconds，and 140（115.5，188） seconds，respectively. The time of manual subtraction and total subtraction of AVA was significantly shorter than that of VCTDSA（P<0.01）. The display rates of the M4 and M5 regions，intracranial bridging veins，superior sagittal sinus，transverse sinus，and sigmoid sinus for AVA and VCTDSA were 0 and 93.33%（140/150），respectively，with a significant difference（P<0.01）. The image quality of internal carotid artery（ICA） 2 and ICA6 of VCTDSA was better than that of AVA（P<0.01）；the percentages of grade I images of ICA2 and ICA6 on VCTDSA were 86.21% （25/29） and 96.55% （28/29），respectively，versus 44.83%（13/29） and 58.62%（17/29） for AVA. The rate of false vascular stenosis showed no significant difference between CTDSA and AVA[1.41%（10/711） vs. 1.13%（8/711），P>0.01]. Conclusion：VCTDSA has a more reliable bone-subtraction effect than AVA on CTA，and it should be used as the preferred bone-subtraction method.

Abstract:Objective：To compare the subtraction effect of volume computed tomography digital subtraction angiography（VCTDSA） and computed tomography angiography with matched mask bone elimination（MMBE） of the head and neck in patients with intracra－nial aneurysm. Methods：A retrospective analysis was conducted on the data of 47 patients who underwent a computed tomography angiography（CTA） of the head and neck and were diagnosed with intracranial aneurysm in our hospital from March 2017 to March 2018. The original images from the head and neck CTA of the above 47 patients were post-processed using the VCTDSA technique on a GE AW4.6 workstation and the MMBE technique on a SIEMENS Syngovia workstation，respectively；the two techniques were compared in terms of automatic subtraction time，manual subtraction time，and total subtraction time；moreover，the bone removal effect after subtraction，blood vessel subtraction effect，and aneurysm display effect were also evaluated. Results：There were significant dif－ferences between VCTDSA and MMBE in the automatic subtraction time，manual subtraction time，and total subtraction time（12 s vs. 76 s，598 s vs. 288 s，and 561.5 s vs. 375 s，respectively）. VCTDSA was significantly superior to MMBE in the subtraction effect of the intracranial segment and the venous sinus of the internal carotid artery as well as in the aneurysm display effect（P<0.01），but was significantly inferior to MMBE in the bone removal effect after subtraction（P<0.01）. For aneurysms of the internal carotid artery siphon，VCTDSA was significantly superior to MMBE in the a－neurysm display effect（P<0.01）. Conclusion：VCTDSA has a high speed of automatic bone removal with a satisfactory effect，and is superior to MMBE in the display effect of blood vessels and aneurysms of the head and neck，which contributes to the observation and diagnosis of intracranial aneurysms. MMBE has a better automatic bone removal effect and can reduce manual subtraction time，but it may achieve a poor overall subtraction effect due to false vascular stenosis and incomplete display of aneurysms caused by excessive subtraction，which is not conducive to the diagnosis of intracranial aneurysms.

Abstract:Objective：To investigate the feasibility of low-dose CT scan in 3D printing of the cerebral artery. Methods：A total of 40 patients who planned to undergo 3D printing of the cerebral artery were randomly divided into groups A and B，with 20 patients in each group. The patients in group A underwent CT at a conventional dose（120 kVp，350 mA） and filtered back projection，and those in group B underwent low-dose CT scan（80 kVp），automatic tube current modulation（ATCM），and adaptive statistical iterative re－construction（ASIR）；the concentration of contrast agent was 350 mgI/mL for both groups. The two-independent-samples t test was used for comparison of clinical data，radiation dose，objective evaluation indices of CT DICOM data，and subjective score of 3D printing quality between the two groups，and the Mann-Whitney U test was used for comparison of non-normally distributed data. Results：There were no significant differences in clinical data between groups A and B（P>0.05）. There was a significant difference in radiation dose between the two groups（P<0.05），and the radiation dose in group B was 68.7% lower than that in group A[（1.30±0.47） mSv vs. （4.15±0.62） mSv]. There was no significant difference in the subjective score of 3D printing quality between the two groups（P>0.05）. As for the objective evaluation indices of CT DICOM data，compared with group B，group A had significantly higher background noise and significantly lower signal-to-noise ratio and contrast-to-noise ratio（P<0.001）. Conclusion：3D printing of the cerebral artery us－ing 80 kVp，ATCM，and ASIR can effectively reduce radiation dose and guarantee the quality of 3D printing.

Abstract:Objective：To investigate the effect of morphological changes（tortuosity and stenosis） of the internal carotid artery（ICA） on cognition. Methods：A total of 39 patients who visited our hospital from October 2017 to June 2018 and 20 subjects as controls were included in the study. The above 39 patients were subdivided into ICA tortuosity group（23 cases） and ICA stenosis group（16 cases） according to the results of cranial-cervical computed tomography angiography（CTA） and cranio-cervical magnetic resonance angiog－raphy（MRA）. Mini-mental state examination（MMSE） and Montreal cognitive assessment（MOCA） were used to evaluate the cogni－tive function in each group. Cerebral white matter lesions were evaluated by the Fazekas scale，and the number of lacunes was calcu－lated for each group. Results：The MOCA score was 27（24，29） for the ICA tortuosity group，28（25，29） for the ICA stenosis group，and 29（28，30） for the control group，with a significant lower score observed in the ICA tortuosity group than in the control group（P<0.05）. There were no significant differences in MMSE score between the three groups. The ICA tortuosity group and ICA stenosis group had significantly different Fazekas scale scores compared with the control group（P<0.05）；the ICA stenosis group had a signifi－cantly larger number of lacunes than the control group and the ICA tortuosity group（9 cases vs 2 cases/1 case，P<0.05）. Compared with the other two groups，the ICA stenosis group had significantly higher prevalence of smoking，drinking，hypertension，and hyper－lipidemia（P<0.05）. Conclusion：Morphological changes（tortuosity and stenosis） of the ICA are related to cerebral white matter lesions，and can lead to a certain degree of cognitive decline.

Abstract:Objective：To determine the consistency in the detection of basilar artery dolichoectasia（BD） by multi-slice spiral CT an－giography（MSCTA） using different post-processing techniques and to compare the diagnostic efficacy of various diagnostic methods. Methods：CT images of 125 patients who underwent head and neck MSCTA in the Radiology Department of our hospital were re－viewed. Of the 125 patients，17 were diagnosed with BD and 108 were diagnosed with non-BD，according to the results of multiplanar reformation（MPR），which is currently the accepted diagnostic method for CTA. The consistency between BD diagnosis results deter－mined by volume rendering（VR），vessel extraction（VE） and inspect & measure tool and MPR diagnosis results for the 125 patients was determined using the Kappa test. Evaluation indices of the VR and VE based diagnostic tests were determined using Medcalc software. Results：Among the 125 patients，12（9.60%） and 14（11.20%） cases of BD were diagnosed by the VR and VE methods，respectively. Consistency in BD diagnosis was moderate between the VR and MPR methods（?资=0.650，P=0.000），and good between the VE and MPR methods（?资=0.816，P=0.000）. The sensitivity（Se），specificity（Sp），positive predictive value（PPV），negative predic－tive value（NPV），and index of validity（IV） of the VR method for BD diagnosis were 58.82%，98.15%，83.33%，93.81%，and 0.928，respectively. The Se，Sp，PPV，NPV and IV of the VE method for BD diagnosis were 76.47%，99.07%，92.86%，96.40%，and 0.960，respectively. Conclusion：VE has higher Se，Sp，PPV，NPV，and IV than VR，and good consistency with MPR in the diagnosis of BD. Therefore，VE is a potential fully quantitative diagnostic method for MSCTA in the diagnosis of BD.

Abstract:Objective：To compare the diagnostic value of volume CT digital subtraction angiography（VCTDSA） and matched mask bone elimination（MMBE） for intracranial arteriovenous malformation（AVM）. Methods：A retrospective analysis was performed on the clinical and imaging data of 37 patients who underwent head or head-and-neck computed tomographic angiography（CTA） and was diagnosed with intracranial AVM by digital subtraction angiography（DSA） from February 2015 to February 2018 in our hospital. The original images were reconstructed by the same operator using VCTDSA and MMBE. The image quality of malformed vessels，feeding arteries，and draining veins，and their automatic subtraction image and manual subtraction image were evaluated，and the post-processing time was compared. Results：There was a significant difference in the automatic，manual，and total subtraction time between VCTDSA and MMBE（P=0.000）. VCTDSA had a shorter time of automatic subtraction than MMBE，but a longer time of manual and total subtraction than MMBE. In 37 patients with intracranial AVM，the image quality of automatic subtraction was mainly classi－fied as grade Ⅱ by MMBE（59.5%，22/37） and grade Ⅲ by VCTDSA（62.2%，23/37）；there was a significant difference between the two methods. The image quality of manual subtraction was mainly classified as grade Ⅰ by VCTDSA（56.8%，21/37） and grade Ⅱ by MMBE（62.2%，23/37）；there was a significant difference between the two methods（P=0.011）. In 19 patients with AVM located in the superficial brain parenchyma，VCTDSA had significantly better image quality of the draining veins than MMBE（P=0.035）. There was no significant difference in the image quality of mal－formed vessels and feeding arteries of all the 37 patients between VCTDSA and MMBE（P=0.317 and 0.739）. Conclusion：VCTDSA has better image quality than MMBE for the AVM located in superficial brain parenchyma，especially the draining veins. However，MMBE subtracts the bone thoroughly，has better image quality of automatic subtraction，and can save more time in post-processing.

Abstract:Objective：To investigate the association between chest computed tomography（CT） findings of pulmonary tuberculosis lesions and the source of offending vessels of hemoptysis in patients with pulmonary tuberculosis and hemoptysis，and to improve the ability of chest computed tomography angiography（CTA） in search for offending vessels of hemoptysis. Methods：A retrospective analysis was performed for the clinical data，digital subtraction angiography（DSA） findings，and CTA findings of 64 patients with pulmonary tuber－culosis and hemoptysis who were treated from June 2013 to October 2018，with focuses on the CT findings of pulmonary tuberculosis lesions，the involvement of the adjacent pleura，and the association of pulmonary and pleural lesions with the source of offending ves－sels of hemoptysis. The association between chest CT findings of pulmonary tuberculosis lesions and offending vessels for hemoptysis was analyzed. Results：With reference to the offending vessels of hemoptysis identified by DSA，all 64 patients had pathologically di－lated bronchial arteries（BA） on CTA，among whom 41 also had involvement of the branches of non-bronchial systemic artery（NBSA） in hemoptysis. The most common NBSA involved was the intercostal artery found in 37 patients（40.2%），followed by the subclavian artery found in 22 patients（23.9%）. Of all 64 patients，17（26.6%） had proliferation of pulmonary lesions，15（23.4%） had exudation of pulmonary lesions，and 32（50%） had fibrosis of pulmonary lesions；26（40.6%） had no or mild pleural thickening，and 38（59.4%） had marked pleural thickening；25 （39.1%） had no or mild adhesion between lesions and the pleura，and 39（60.9%） had severe adhesion. The numbers of patients with pathological NBSA in each group were 6（35.3%），6（40.0%），29 （90.6%）；4（15.4%），37（97.4%），2（8.0%），and 39（100%），respectively，and there was a significant difference between groups（P<0.01）. The extent of lesions and the presence or absence of bronchiectasis in lesions were not significantly associated with the offending vessels of hemoptysis. Conclusion：In patients with pulmonary tuberculosis，chest CT findings of pulmonary tuberculosis lesions are closely associated with the source of offending vessels of hemoptysis. For patients with marked fibrosis of pulmonary lesions，marked thickening of the adjacent pleura，and severe adhesion between lesions and the pleura，CTA should be performed to evaluate BA，and it is also necessary to determine whether NBSAs are responsible for hemoptysis.

Abstract:Objective：To explore the visibility of thrombus in the pulmonary trunk on plain computed tomography（CT） scan and its influencing factors. Methods：A retrospective analysis was performed on the clinical and radiological data of 79 patients who were diagnosed with thrombus in the pulmonary trunk by CT pulmonary angiography（CTPA） from June 2017 to October 2018. Based on the CTPA results，the visibility and characteristics of thrombus in the pulmonary trunk on plain CT images were evaluated；the rela－tionship of thrombus features on plain CT images with diameters of the pulmonary artery and ventricular cavity and related laboratory indices was evaluated. Results：In the 79 patients，6（7.5%） had simple main trunk embolism，40（50.6%） simple distal trunk embolism，and 33（41.9%） main trunk embolism with distal embolism. According to the plain CT images，34（43.0%），23（29.1%），and 22（27.9%） patients had intravascular thrombus of low，equal，and high densities，respectively. There was a significant difference in the CT value of thrombus between the three groups[（21.5±6.1） HU vs. （37.9±7.7） HU vs. （63.4±7.0） HU，P=0.000]. However，there was no significant difference in the CT value of blood in adjacent vessels between the three groups[（45.4±7.9） HU vs. （38.6±5.0） HU vs. （40.7±5.2） HU，P>0.05]. According to the CTPA images，the most common type of thrombus was central type（30 patients，38.0%），followed by acute angle with the vessel wall（25 patients，31.6%），and obtuse angle with the vessel wall（16 patients，20.2%）. Conclusion：For patients with suspected pulmonary embolism，a high possibility of thromboembolism should be considered when high- or low-density patchy shadows are detected in the center or one side of the pulmonary trunk lumen on plain CT scan.

Abstract:Objective：To explore the practical value of the optimal time for pulmonary arterial and venous imaging by a wide-area de－tector using perfusion scanning mode by comparing the image quality and radiation dose of multi-phase computed tomography an－giography（CTA） and conventional single-phase CTA. Methods：Contrast-enhanced computed tomography（CT） of the lung was per－formed in 108 patients scheduled for right upper lung lobe resection due to ground-glass opacity（GGO）. According to the examination results of the Revolution CT，the patients were divided into 2 groups（54 cases in each group）：group A（using perfusion scanning） and group B（using automatic bolus tracking triggered by contrast enhancement）. Patients in group A underwent multi-mode CT examination using perfusion scanning，including plain CT scan and CT perfusion（CTP） of the lung. After contrast agent injection，axial CT scan was performed on the 160 mm layer in a region of interest with a phase interval of 2 seconds until the end of pulmonary venous phase. Patients in group B underwent conventional CT using automatic bolus tracking triggered by contrast enhancement. The pulmonary trunk，right pulmonary artery，right upper lobe pulmonary artery，right apical pulmonary artery，aorta，and their accompanying veins were selected to be measured on the scanning images taken during the pulmonary arterial and venous phases for all the patients；the CT values and noise standard deviation（SD） were obtained from the measurement，and the differences in CT values between the four groups were calculated；meanwhile，an integral method was used for evaluation of visualization of grade 5 or 6 pulmonary arteries and veins. Results：There were no significant differences between the two groups in the CT values of grade 1-4 pulmonary arteries and veins，except grade 3 and 4 pul－monary arteries（P=0.010 and 0.003），on computed tomography pulmonary angiography（CTPA）（P>0.05）. Compared with group B，group A had significantly larger CT value differences between pulmonary arteries and their accompanying veins on CTPA and between pulmonary veins and their accompanying arteries on computed tomography pulmonary venography（CTPV）（all P<0.05）. In the evaluation of visualization of grade 5 or 6 pulmonary arteries and their accompanying veins by the integral method，the results showed that both groups had a score of 3 in the visualization of pulmonary arteries，but had significantly different scores in the visualization of small pulmonary venous branches（group A：3.00[3.00，3.00]，group B：2.00[1.75，3.00]，Z=2.814，P=0.005）. Meanwhile，there were no significant differences between the two groups in the SD values of pulmonary trunk（group A：28.45±3.47，group B：29.47±3.80，t=0.627，P=0.539） or right upper pulmonary vein（group A：27.27±7.56，group B：27.76±6.44，t=0.156，P=0.878）. Conclusion：The perfusion-like method used by a wide-area detector can not only meet the requirements for CT values of the pulmonary arteries and veins，but it can also effectively separate the pulmonary arteries from the veins，which is especially helpful for thoracoscopic pulmonary segmental resection due to GGO in clinical practice；therefore，it holds promise for clinical application.

Abstract:Objective：To investigate the differences in coronary artery branch diameter，distribution type，and aortic sinus diameter on coronary CT angiography（CCTA） between the healthy Han and Uygur adults in Southern Xinjiang，China and their correlation. Methods：A retrospective analysis was performed for the CCTA data of the healthy Han and Uygur adults who underwent physical ex－amination in The First People’s Hospital of Kashgar from January 2016 to January 2017. A total of 300 healthy Uygur adults with normal coronary artery（173 male and 127 female adults aged 40-60 years，with a mean age of 50.03±7.82 years） and 300 healthy Han adults with normal coronary artery（193 male and 107 female adults aged 40-60 years，with a mean age of 51.36±8.40 years） were randomly selected. Curved planar reformation，maximum intensity projection，and volume rendering reconstruction of the coronary artery were performed，and the American Heart Association 15-segment method was used to measure the differences in the diameter of the right coronary artery，the left anterior descending artery，the circumflex coronary artery，and the proximal and middle segments of the obtuse marginal branch，aortic sinus diameter，and the distribution of coronary artery between the Han and Uygur population. Results：Compared with the Han group，the Uygur group had significantly larger diameters of the left anterior descending artery，the circumflex coronary artery，and the proximal and middle segments of the obtuse marginal branch（P<0.05）. Among the 300 healthy Han adults，24（8.0%） were left dominant，246（82.0%） were right dominant，and 30 （10.0%） were balanced. Among the 300 healthy Uygur adults，104（34.66%） were left dominant，184（61.33%） were right dominant，and 12 （4.0%） were balanced；there was a significant difference in the distribution of dominant coronary arteries between the two groups（P<0.05）. There were no significant differences be－tween the two groups in diameter of the right coronary artery and aortic sinus diameter（P>0.05）. Conclusion：There are differences in coronary artery diameter and distribution type between the healthy Uygur and Han adults in Southern Xinjiang.

Abstract:Objective：To evaluate the clinical value of dual-energy CT in the fusion imaging of pulmonary artery，pulmonary vein，and pulmonary nodules. Methods：A total of 56 patients with <3 cm-diameter ground glass nodules（GGNs） who underwent preoperative pulmonary vascular fusion imaging were randomly divided into control group（n=28） and observation group（n=28）. Routine CT scan was performed in the control group，and dual-energy CT scan and post-spectral processing were performed in the observation group. The quality of vascular images was compared between the two groups. Monoenergy data at 60 keV and 74 keV were generated from the scan data of the observation group for intra-group comparison. Results：The pulmonary artery，pulmonary vein，and pulmonary nodules were clearly displayed using 60 keV single energy imaging in 28 patients of the observation group. The relationship among the pulmonary artery，pulmonary vein，and pulmonary nodule could be clearly demonstrated by fusion imaging. The relationship among distal blood supply，reflux blood vessels，and pulmonary nodules could not be completely displayed for 7 patients in the control group. Although this relationship was visible in the other 21 patients，the structure of distal vessels was not as clear as that in the 60 keV single energy imaging group. Subjective evaluation and objective scores of the CT value and signal-to-noise ratio were significantly different between the 60 keV group and the control group，and between the 60 keV and 74 keV imaging data in the observation group （all P<0.05）. Conclusion：Dual-energy CT imaging at 60 keV monoenergy provides superior fusion of the pulmonary artery，pul－monary vein，and pulmonary nodules to conventional CT scan.

Abstract:Objective：To investigate the feasibility of a contrast agent injection protocol based on body mass index（BMI） multiplied by injection coefficient in 256-slice spiral computer tomography（CT） for coronary computed tomographic angiography（CTA）. Methods：A total of 300 patients with the symptom of chest pain who underwent coronary CTA were randomly divided into groups A，B，and C. The injection rate was 0.15×BMI（mL/s） in group A，0.20×BMI（mL/s） in group B，and 0.25×BMI（mL/s） in group C，and the amount of contrast agent was calculated based on injection rate×9. Image quality was evaluated after scanning，and the concentration of the contrast agent was measured at the root of the aortic valve and at the opening of the left anterior descending coronary artery（LAD），the proximal portion of the left circumflex artery （LCX），and the right coronary artery（RCA）. Results：Group B had a signifi－cantly higher excellent rate of image quality than the other two groups. There were significant differences between the three groups in the CT values of the aorta and the three important branches of the coronary artery（LAD，LCX，and RCA）（P<0.001）. There was no significant difference in noise between the three groups（P>0.05），while signal-to-noise ratio and contrast/noise ratio gradually in－creased from group A to group C. Conclusion：Injection rate and amount of contrast agent based on BMI multiplied by injection coef－ficient for coronary CTA can meet the needs of clinical diagnosis and significantly reduce the amount of contrast agent.

Abstract:Objective：To investigate the clinical value of the third-generation dual-source CT prospective ECG-gated sequence scan－ning mode in the diagnosis of complex congenital heart disease. Methods：A total of 43 patients who were clinically diagnosed with complicated congenital heart disease and underwent surgery were enrolled，and the results were used as the gold standard to compare the detection rate and overall diagnostic efficacy of heart dual-source CT prospective ECG-gated sequence scanning and echocardio－graphy. Results：A total of 187 deformities were found in 43 patients after surgery；155 deformities were detected by dual-source CT，and 153 were detected by echocardiography；the overall detection rates of dual-source CT and echocardiography were 82.89% and 81.82%，respectively（ ?字２=0.074，P=0.786）. For deformities at cardiovascular junctions，dual-source CT had a detection rate of 100% and echocardiography had a detection rate of 90.91%（ ?字２=2.095，P=0.148）；for intracardiac malformations，dual-source CT had a detection rate of 62.35% and echocardiography had a detection rate of 81.18%（ ?字２=7.430，P=0.006）；for pericardial vascular malfor－mations，the detection rates of dual-source CT imaging and echocardiography were 100% and 80.00%，respectively，and there was a significant difference between the two methods（ ?字２=17.778，P=0.001）. Third-generation dual-source CT had a positive predictive val－ue of 98.05%，a negative predictive value of 96.43%，an accuracy of 96.64%，a specificity of 99.69%，and a sensitivity of 80.75%，and echocardiography had a positive predictive value of 99.35%，a negative predictive value of 96.52%，an accuracy of 96.90%，a specificity of 99.90%，and a sensitivity of 81.28%. Conclusion：Compared with echocardiography，dual-source CT imaging has obvi－ous advantages in the diagnosis of pericardial vascular malformations in complex congenital heart disease. There is no significant dif－ference in overall detection of lesions between dual-source CT imaging and echocardiography.

Abstract:Objective：To investigate the feasibility of one-stop scanning of head and neck arteries and the aorta. Methods：A retro－spective analysis was performed for 40 patients who underwent head and neck computed tomography（CT） angiography（CTA） and thoracic and abdominal CTA. These patients were divided into group A and group B according to the scanning method. Group A underwent one-stop scanning of head and neck arteries and the thoracic and abdominal aorta，while group B underwent head and neck CTA and thoracic and abdominal CTA separately. Subjective scoring and objective statistical analysis were performed on the images obtained in the two groups. Results：CTA images of both groups met the diagnostic requirements. There was no significant difference in CT value between the two groups（P>0.05）. No significant differences were observed between the two groups in contrast-to-noise ratio（CNR） or standard deviation（SD） of the aortic arch，the abdominal aorta，and the common iliac artery（P>0.05）. Compared with group A，group B had significantly higher CNR of the middle cerebral artery，the vertebral artery，and the common carotid artery and significantly lower SD of these arteries（P<0.05）. There was no significant difference in SD of the aortic arch，the abdominal aorta，and the common iliac artery between the two groups（P>0.05）. Group A had a significantly lower dose of contrast agent than group B（104.70±10.62） mL vs. （146.10±12.48） mL，t=-11.297，P<0.001]. Conclusion：Head and neck CTA combined with thoracic and abdominal CTA can meet the needs for diagnosis，reduce examination times and the dose of contrast agent，and optimize the examination process.

Abstract:Objective：To investigate the application value of “one-stop” scanning combined CT angiography（CTA） for coronary and head-neck arteries and aorta with wide detector CT. Methods：Images of 80 patients who underwent CTA scans were analyzed. These patients were divided into 2 groups：Group A（n=40） and Group B（n=40）. Separate contrast injection protocol for aortic CTA with suspected aorta dissection and combined head-neck and coronary CTA for suspected cardiovascular disease were carried out on Group A. One-stop scan for combined coronary，head-neck and aortic CTA scans were carried out on Group B. Subjective evaluation and objective evaluation were performed for both two groups. Image quality，contrast dose，radiation dose，the total scan time between the two groups were compared. Results：There was no statistic difference in age，gender，heart rate，BMI and radiation dose between the two groups（P>0.05）. There was no statistic difference in subjective evaluation（P>0.05） and image quality in both groups met the requirement of diagnosis. There was no statistic difference in CT value and contrast nosie ratio（CNR） among M1 segment of the mid－dle cerebral artery，common carotid artery，vertebral artery V4 segment，RCA，LAD，LCX，aortic root，descending aorta，abdominal aor－ta and common iliac artery（P>0.05）. However，there were statistically significant differences in contrast dose and scan time between the two groups（P<0.05）. Compared with Group A ，the contrast dose and scan time reduced 45% and 52%，respectively，in Group B. Conclusion：Wide-detector CT can provide the “one-stop” examination for coronary，head-neck and aortic arteries with single contrast injection to obtain equivalent image quality as the conventional dual-injection protocol with reduced contrast dose and examina－tion time. It is useful for preoperative evaluation of patients with aortic dissection.

Abstract:Objective：To investigate the feasibility of enhancing image quality of abdominal aorta Computed Tomography Angiography （CTA） under low contrast agent and individualized injection of low injection rate with non-linear blending（NLB） of third-generation dual-resource CT device. Methods：A total of 30 patients who were likely to undergo dual-energy abdominal aorta CTA were enrolled. The third-generation dual-source CT device with a tube voltage at 70/sn150 kVp combined with intelligent tube current adjustment technology of CARE Dose 4D was used. The dose of contrast medium was obtained in accordance with patients’ weight plus 0.5，and then the injection velocity was defined by contrast agent/examining time（scanning time + delay time after achieving the trigger threshold value）. NLB image and regular linear blending（LB） with a fusion coefficient of 0.5 were re-constructed. Images’ CT values，signal to noise ratio（SNR） and contrast to noise ratio（CNR） on abdominal aorta and initial part of its main branches in two groups were evaluated by using paired t-test. Subjective quality score of images in two group was compared via Mann-Whitney U test and consistency of the score was analyzed by Kappa test. Results：The average effective radiation dose was （4.80±0.77） mSv，the average iodine intake was （12.30±1.71） g，the average contrast volume was （35.3±4.91） mL，and the average injection velocity was （3.30±0.47） mL/s. Vascular CT value，SNR and CNR in the NLB group were significantly increased than those in LB group（P<0.05）. Average CT value and SD value of muscles at the back of chest in two groups had no statistically significant difference（P>0.05）. Subjective score of images in two groups had good consistency（?资=0.618，P<0.05），and it in the NLB group was higher than that in the LB group，with an improvement of 0.55（P<0.05）. Conclusion：NLB of third-generation dual-source CT device under low contrast agent and individualized injection of low injec－tion rate can significantly improve the image quality of abdominal aorta CTA.

Abstract:Objective：To study the practical value of computed tomography angiography（CTA） with monoenergetic imaging combined with iterative reconstruction using a medium-sharp convolution kernel（B60f，SAFIRE） in the diagnosis of in-stent restenosis（ISR） of the lower extremities. Methods：CTA of the lower extremity arteries was performed in 72 patients（37 males and 35 females） with a stent implanted in the femoral artery. Among the above patients，25 underwent dual-energy scanning combined with iterative recon－struction using a medium-sharp convolution kernel（B60f，SAFIRE） and were subdivided into two monoenergetic imaging groups（70 keVsharp and 80 keVsharp）；47 underwent 100-kV scanning and were subdivided into 100 kVstandard group（23 cases，using adaptive statistical iterative reconstruction[50% ASIR]） and 100 kVsharp group（24 cases，using iterative reconstruction with a medium-sharp convolution kernel[B60f，SAFIRE]）. These groups were com－pared for image noise（standard deviation[SD]），signal-to-noise ratio（SNR），contrast-to-noise ratio（CNR），stent-vessel deviation（SVD），and measured-actual deviation（MAD）；the diagnostic accuracy for ISR was evaluated by taking into ac－count the results of vascular ultrasound or digital subtraction angiography. Results：In groups of the same energy level and processed with different reconstruction methods，the image noise（SD） was significantly lower in the 100 kVstandard group than in the 100 kVsharp group；there were no significant differences between groups in SNR or CNR（P>0.05）. Between groups of different energy levels and processed with the same reconstruction method，there were significant differences in image noise（SD）（70 keVsharp<80 keVsharp<100 kVsharp，P<0.05） and intraluminal SNR and CNR（100 kV sharp<70 keVsharp<80 keVsharp，P<0.05）. There were significant differences between groups in SVD（70 keVsharp<80 keVsharp<100 kVsharp<100 kVstandard，P<0.05），MAD（80 keVsharp<100 kVsharp<70 keVsharp<100 kVstandard，P<0.05），subjective image quality score（70 keVsharp<100 kVs－tandard<100 kVsharp<80 keVsharp，P<0.05），and diagnostic accuracy for ISR（70 keVsharp（71.04%）<100 kVstandard（86.19%）<100 kVsharp（91.27%）<80 keVsharp（95.8%），（ χ2=9.95，P=0.019），κ=0.743，P<0.05）. Conclusion：Monoenergetic imaging combined with iterative reconstruc－tion using a medium-sharp convolution kernel（B60f，SAFIRE） in the 80 keVsharp group can help optimize the image quality of CTA for stent-implanted vessels and improve the diagnostic accuracy for ISR.

Abstract:Objective：To examine the effects of 80 kVp on radiation dose，iodine intake，and image quality for abdominal computed to－mography angiography（CTA）. Methods：Abdominal CTA was performed in 49 patients（20≤BMI≤23） using GE Revolution CT. The patients were divided based on tube voltage into group A（n=27，80 kVp） and group B（n=22，120 kVp）. With the exception of kVp，all scanning parameters in the two groups were the same：automatic mA，50% ASIR-V，default NI，1.25 mm thickness，HD mode，Stnd reconstruction，80 mm detector width，and 0.5 s scan time. Iohexol contrast agent（350 mgI/mL） was administered at 300 mgI/kg（4 mL/s） in group A and at 500 mgI/kg（5 mL/s） in group B，and was automatically tracked at a threshold of 220 HU. The mean CT and SD values of the abdominal aorta，abdominal trunk，common hepatic artery，splenic artery，superior mesenteric artery，and erector spinae at those levels were measured. Image quality（volume rendering and maximum intensity projection），contrast-to-noise ratio（CNR） and signal-to-noise（SNR） of the abdominal artery，volume CT dose index（CTDIvol），dose-length product（DLP），and total iodine intake were determined and compared between the two groups using the SPSS software. Results：There was no significant difference in the CTA image score between group A（4.58±0.51；κ=0.915） and group B（4.32±0.58，κ=0.946）（P>0.05）. The CT values of the abdominal aorta，common hepatic artery，splenic artery，and superior mesenteric artery were signifi－cantly higher in group A（584.09±63.54 HU，503.22±58.72 HU，486.44±74.47 HU，and 535.23±54.94 HU，respectively） than in group B（407.89±60.78 HU，368.57±45.31 HU，371.88±49.55 HU，and 387.83±55.85 HU，respectively）（all P<0.05）. The SNRs and CNRs were also significantly higher in group A than in group B（both P<0.05）. Compared with group B，group A had significantly lower CTDIvol（3.34±0.22 mGy vs. 8.78±0.93 mGy；61.96% reduction） and DLP（172.77±13.75 mGy·cm vs. 438.30±58.23 mGy·cm；60.58% reduction）. The total iodine intake of each patient was reduced by 39.67% in group A（300 mgI/kg） compared with group B （500 mgI/kg）. Conclusion：Abdominal CTA at a low tube voltage of 80 kVp（20 kg/m2≤BMI≤23 kg/m2） significantly reduces the radiation dose and contrast agent intake in patients，and improves CNR and SNR of the abdominal aorta and its major branches.

Abstract:Objective：To evaluate the image quality and radiation dose of dual-source computed tomography at ultra-low tube voltage （70 kV）. Methods：A total of 90 patients undergoing CT angiography（CTA） of the abdominal aorta and lower extremity arteries were randomly divided into three groups：group A：70 kV，dual-source，and sinogram-affirmed iterative reconstruction（strength level 3）（SAFIRE-3）；group B：100 kV，single-source，and filtered back projection；group C：70 kV，single-source，and SAFIRE-3. Then，the CT values，signal-to-noise ratio（SNR），and contrast-to-noise ratio（CNR） of four vascular regions of interest （ROIs） of the abdominal aorta，the common iliac artery，the femoral artery，and the radial artery were measured，image quality was subjectively scored，and the radiation dose was compared between the three groups. Results：Groups A and C had significantly higher CT values of three ROIs of the abdominal aorta，the common iliac artery，and the femoral artery than group B，and group A had significantly higher SNR and CNR of the three vascular ROIs than groups B and C（P<0.05）. The image quality of the distal small vascular branches was signif－icantly higher in group A than that in groups B and C（P<0.05），but there was no significant difference between group B and group C（P>0.05）. The volume CT dose index volume and dose-length product were significantly different between the three groups（P<0.05），and the values were highest in group B and lowest in group C. The radiation dose in group A was 24% higher than that in group C but 18% lower than that in group B. Conclusion：High-pitch dual-source CTA of the lower extremities at ultra-low tube voltage（70 kV） combined with iterative reconstruction tech－nique can reduce radiation dose，increase the image quality，and contribute to the imaging of distal small vascular branches.

Abstract:Objective：To investigate the value of computed tomography venography/angiography（CTV/A） via both great saphenous veins in the imaging diagnosis of iliac vein compression syndrome（IVCS）. Methods：A retrospective analysis was performed on 109 cases（49 males and 60 females） diagnosed as IVCS by digital subtraction angiography. They were randomly divided into group A（57 cas－es；25 males and 32 females） and group B（52 cases；24 males and 28 females）. Group A and group B were injected with a contrast agent through both great saphenous veins（below the knee joint） and both dorsalis pedis veins，respectively. A bolus tracking scan was performed in both groups；we monitored the abdominal aorta and the inferior vena cava in group A and group B，respectively. Arteri－ovenous nicking and distorted open collateral vessels were displayed by postprocessing methods such as three-dimensional volume rendering，maximum intensity projection，multiplanar reformation，and curved planar reconstruction. Three experienced diagnosticians evaluated the image quality，abdominal aorta-inferior vena cava contrast ratio（direct sign），and collateral display rate（indirect sign）. Results：①The display rate of the distorted pelvic vein，caudal venous plexus，abdominal wall branches was significantly higher in group A than in group B（58.14% vs. 13.95%，P<0.001）；the display rate of varicose veins in both lower limbs was not significantly different between group A and group B（98.83% vs. 96.51%，P=0.312）. ②There was no significant difference in the vascular density of the inferior vena cava trunk between group A and group B（354.07±26.49 HU vs. 303.59±30.57 HU，t=11.57，P<0.001）；group A had a significantly higher vascular density of the iliac artery trunk than group B（177.28±14.95 HU vs. 74.24±13.49 HU，t=47.45，P>0.001）. ③The incidence of contrast agent eddy current was significantly lower in group A than in group B（23.26% vs. 62.79%，P<0.001）. ④Group A had a significantly higher diagnostic accuracy rate of IVCS than group B（93.6% vs. 10.22%，P<0.001）. Conclusion：Lower limb CTV/A via both great saphe－nous veins can clearly demonstrate iliac arteriovenous anatomy and the direct and indirect signs of IVCS，thus improving image quality and the diagnostic accuracy rate of IVCS.

Abstract:Objective：To investigate the application of CT angiography（CTA） in the optimal scanning scheme for accurate display of peripheral arteries in patients with diabetic foot and its effect on image quality. Methods：A total of 75 patients with diabetes underwent CTA of lower extremity arteries with 64-slice CT，and they were randomly divided into control group and optimization group. In the control group，the contrast agent was injected in a single time phase，with total iodine content=body weight（kg）×450 mg and iodine flow rate=total iodine content injected/28/s，and the locator was located at the distal end of the abdominal aorta；the scan was triggered when the CT threshold of the artery reached 300，and the scan was started after preparation for 8 seconds，with Rotation time of 1 s and Pitch of 0.9. In the optimization group，the contrast agent was injected consecutively in two phases，with iodine dose=body weight（kg）×450 mg×60% and iodine flow rate=iodine dose at first injection/14/s for the first phase and iodine dose=body weight（kg）×450 mg×40% and iodine flow rate=iodine dose at second injection/14/s for the second phase，and the locator was located in the popliteal artery；the scan was triggered when the CT threshold of the artery reached 90，with Rotation time of 0.7 s and Pitch of 0.9. The images were processed by EBW post-processing workstation；a senior technician measured the CT values of each segment of lower extremity blood vessels and determined the objective scores of these results，and two physicians with an intermediate professional title or above determined the subjective score of the post-processing images. Results：Of all 37 patients in the control group，26 had images which met the diagnostic requirements，among whom 11 had unclear display of lower extremity peripheral arteries（dorsal pedal arteries） at both sides. Of all 38 patients in the optimiza－tion group，36 had images which met the diagnostic require－ments，among whom 2 had unclear display of lower extremity peripheral arteries（dorsal pedal arteries） at both sides. There was a significant difference in the score of peripheral arteries between the two groups（0.910±0.072 vs. 0.950±0.050，P<0.05），while there were no significant differences in the scores of the other regions between the two groups（P>0.005）. There were significant differences between the two groups in the objective scores of the distal pe－ripheral arteries（129.0±27.7 vs. 90±13.8，P<0.05） and the iliac artery（426.0±54.5 vs. 392.0±46.2，P<0.05），while there were no significant differences in the scores of the other regions between the two groups（P>0.05），suggesting that the optimization group had more abundant peripheral artery images and lower CT values of proximal vessels to obtain more homogeneous vascular images. Conclusion：CTA for optimal design in the examination of patients with diabetic foot can greatly improve the accuracy of the display of lower extremity peripheral arteries in patients with blood circulation disorders including diabetic foot，and the success rate of the dis－play of peripheral arteries can be increased by 24.4%. CTA can meet the diagnostic requirements，improve the quality of the images of lower extremity arteries，and provide rich information for diagnosis，thus providing better imaging service for patients with diabetic foot.

Abstract:Objective：To evaluate the radiation dose and image quality of pixel shine（PS） algorithm at 80 kVp in direct computed to－mography（CT） venography of the lower extremities. Methods：Forty-one patients who were clinically diagnosed with lower extremity varices and underwent direct CT venography of the lower extremities were randomly assigned to experimental group（80 kV） and con－trol group（100 kV）. Filtered back projection（FBP） and PS algorithm were used for reconstruction in the control group and the exper－imental group，respectively. The volume CT dose index（CTDIvol） and the dose-length product（DLP） were compared between the two imaging techniques. The images of the fifth lumbar vertebra，the femoral head，and the popliteal fossa were selected. Two radiologists gave subjective scores for quality and noise of the above images. Venous vessel CT value，image noise，signal-to-noise ratio（SNR），and contrast-to-noise ratio（CNR） were measured and calculated. Results：The experimental group had significantly lower CTDIvol and DLP than the control group（t=-89.95，P<0.01；t=-35.83，P<0.01）. The two radiologists achieved a high consistency in subjective evaluation of image quality（?资=0.78，P<0.01）. There were no significant differences in the subjective scores for image quality of the infe－rior vena cava，the femoral vein，or the popliteal vein between the two groups（P=0.17，P=0.92，and P=0.75）. There was no difference in image noise between the two groups. However，the experimental group had significantly higher vessel CT value，SNR，and CNR than the control group（all P<0.01）. Conclusion：PS algorithm at 80 kVp can be routinely used in direct CT venography of the lower extremities to reduce radiation dose and improve vessel CT value，SNR，and CNR.

Abstract:Objective：To investigate the feasibility and operating points of ultrasound guidance in indwelling needle puncture in pa－tients with difficulty in venipuncture during contrast-enhanced computed tomography（CT）. Methods：A total of 46 patients with poor vascular conditions were enrolled as control group and were given venipuncture with the conventional indwelling needle puncture method，and 43 patients with failed venipuncture were enrolled as experimental group and were given ultrasound-guided venipunc－ture. The chi-square test was used to compare puncture success rate and complications between two groups，and the paired samples t-test was used to compare the time spent on vessel selection，number of times of puncture，and number of times of needle insertion between two groups. Results：Three patients in the control group had successful puncture，while all 43 patients in the experimental group had successful puncture under ultrasound guidance，among whom 38 had successful one-time puncture and 5 had successful puncture after two times of puncture，resulting in a puncture success rate of 100%. There were significant differences between the ex－perimental group and the control group in the success rate of one-time puncture（ χ2=70.940，P=0.000） and overall success rate（ χ2= 77.770，P=0.000），and the experimental group had a significantly lower incidence rate of complications than the control group（ χ2= 15.151，P=0.000）. Compared with the control group，the experimental group had significantly shorter time spent on vessel selection （3.65±1.571 vs. 36.86±7.11，t=32.412，P<0.01） and significantly lower numbers of times of puncture（1.12±0.32 vs. 3.56±0.50，t=31.866，P<0.01） and needle insertion（1.21±0.47 vs. 7.56±1.65，t=23.685，P<0.01）. Conclusion：In patients with difficulty in venipuncture，ultrasound-guided indwelling needle puncture can improve puncture success rate，alleviate pain，and help them to undergo a successful CT examination. The operation is simple and safe，thus holding promise for clinical application.

Abstract:High-pressure injection of iodine contrast media（ICM） through vascular access is a necessary step in contrast-enhanced CT，but it is hard for patients with severe and acute diseases or especially-bad vascular conditions to reach peripheral vascular ac－cess. Therefore，central venous catheter can be an alternative. This paper reviewed studies at home and abroad concerning the safety of high-pressure injection of ICM via central venous catheter，providing a reference to infusion channels for patients with particularly difficult puncture and a guidance for further research.

Abstract:Objective：To investigate the effects of different scanning methods and medication with different computed tomography （CT） devices on subjects and their nursing care during coronary angiography. Methods：Based on the coronary computed tomography angiography（CCTA） guidebooks，subjects were divided into the group A and group B. Group A had scanning scheme a of the comput－ed tomography angiography（CTA） using the 2016 Siemens second-generation dual-source CT device in our hospital and medication in accordance with nurses’ experience；group B had scanning scheme b of coronary CTA using 2017 General Electrical（GE） wide detec－tor CT device in our hospital and medication based on iodine flow rate. The one-time examination success rate，contrast agent ex－travasation，adverse reaction rate，and the satisfaction of the subjects were observed. The difference was considered statistically signifi－cant if P<0.05. Results：Requirements for subjects’ cooperation，subjects’ individual factors，failure rate，rescanning rate and the inci－dence of contrast agent extravasation in the group B were lower than those in the group A；satisfaction degree in the group B was higher than that in the group A；all differences had statistical significance（P<0.05）. However，the incidence of adverse reactions in two groups had no statistically significant difference（P>0.05）. Conclusion：GE wide detector device combined with the iodine flow rate has low requirement for subjects’ cooperation and high one-time success rate，which can effectively improve the patients’ satisfaction degree and simplify the nursing process， worthy of promotion and application in clinical medical laboratory.

Abstract:Acute respiratory distress syndrome（ARDS） is an intractable hypoxemia caused by injury of pulmonary capillary endothe－lial cells and alveolar epithelial cells. Pulmonary computed tomography（CT） plays an important role in the diagnosis and evaluation of ARDS，whereas pulmonary CT angiography plays an important role in the diagnosis and treatment of chronic obstructive pulmonary disease，pulmonary embolism，and pulmonary hypertension. However，the use of pulmonary CT angiography in the evaluation of lung perfusion and vascular changes during ARDS has rarely been examined. This article reviews the application of pulmonary CT angiog－raphy in pulmonary diseases，the latest progress in pulmonary vascular CT imaging，and the pathogenesis and pathophysiological changes of ARDS. We will briefly discuss the current application of pulmonary vascular CT imaging in ARDS and the feasibility of using imaging changes to evaluate ARDS.

Abstract:Diffusion-weighted imaging（DWI） is a noninvasive technique for measuring the diffusion of water molecules in living tissue. It can not only provide a tissue contrast different from conventional magnetic resonance imaging（MRI），but also obtain quantitative parameters to indirectly evaluate pathological changes in organs or tissues. Based on these advantages of DWI sequences，scholars have tried to apply it in MRI qualitative diagnosis，differential diagnosis，and evaluation of treatment outcomes of central nervous system，breast，liver，rectum，uterus，prostate，and other organ diseases. It has achieved encouraging results in the central nervous system disorders. In this article，we review the research status and advances in the application value of hyperintensity on DWI and apparent diffusion coefficient in the diagnosis and differential diagnosis of central nervous system disorders.

Abstract:Objective：To investigate the influence of particle size of superparamagnetic iron oxide（SPIO） nanoparticles on T1-T2 re－laxation efficiency，as well as the features of ultra-small SPIO（USPIO） as the T1-T2 double contrast enhancer in in vivo imaging. Methods：The coprecipitation method was used to prepare three types of SPIO nanoparticles with different particle sizes. The basic physical-chemical and magnetic properties of the samples were measured，and a 3.0 T MRI imager was used to investigate the imaging properties of USPIO as the T1-T2 double contrast agent in rats under different MRI sequences. Results：Three types of SPIO nanopar－ticles （A：14.14±4.94 nm；B：28.30±7.65 nm；C：93.81±33.01 nm） were successfully prepared and the relaxation properties of T1 and T2 at different magnetic field intensities were measured. SPIO nanoparticles with a smaller particle size had a lower r2/r1 ratio（0.5 T：2.14） and were the potential T1-T2 double contrast enhancers；such nanoparticles had a significantly lower r2/r1 ratio in low mag－netic field and might help with T1 contrast-enhanced imaging. The imaging of the rats showed that USPIO significantly reduced the T2 signal intensity of the liver on T2WI and increased the T1 signal intensity of the liver and the cardiovascular system on short-TE T1WI，with a longer time window for imaging than small-molecule contrast agents. Conclusion：Particle size is one of the important parameters affecting the relaxation efficiency of SPIO. USPIO has a lower r2/r1 ratio and can be used as the potential T1-T2 double contrast enhancer.

Abstract:Objective：To analyze the anatomical information of coronary-pulmonary fistula（CPF） based on the examination data from coronary computed tomography angiography（CCTA）. Methods：A retrospective analysis was conducted on the CCTA data of 71 patients with CPF. Analyses and calculations were performed on the fistula feeding arteries，location and size of the fistula orifice and its relationship with surrounding anatomical structures，type of inflow to the fistula，and diameters of the aorta and the pulmonary artery with the 95% confidence intervals[CIs] evaluated for the fistula orifice size，diameter of its feeding arteries，and distance between the fistula orifice and the pulmonary valve. Statistical analyses were made on the differences in diameters of feeding arteries and the correlation of the width of the fistula orifice with the diameters of the aorta，the pulmonary artery，and the dominant feeding arteries. In addition，statistical analyses were made on the differences between cases with different types of inflow to the fistula in terms of the fistula orifice size and the diameter of feeding arteries. Results：Ninety-eight point five percent（70/71） of the cases had a fistula in the pulmonary trunk in the direction of 12 o’clock to 3 o’clock，60.6%（43/71） had bilateral blood supply，9.9%（7/71） had a blood supply from the right coronary artery，29.6%（21/71） had a blood supply from the left coronary artery，42.3%（30/71） showed a “puff of smoke” sign，and 46.5%（33/71） showed an “ejecting” sign. After excluding the isolated case with a fistula in the left pulmonary trunk，mean values of fistula size，distance between the fistula orifice and the pulmonary valve，and diameter of feeding arteries were （2.5±1.1），（3.1±2.0），and （15.1±6.7） mm，respectively，with the corresponding 95%CI as 2.6～3.6，13.8～15.5，and 2.2～2.8 mm，respectively. The location of feeding arteries from the right coronary artery was significantly closer to the fistula com－pared with that from the left coronary artery（t=11.03，P<0.05），but there was no significant difference in the diameter of feeding arteries from both sides（P>0.05）. The fistula orifice size was positively correlated with the diameter of the aorta and the feeding arteries（r=0.505，P<0.05），but not correlated with the diameter of the pulmonary artery. There were no significant differences between cases with different types of inflow to the fistula in terms of fistula orifice size or the diameter of feeding arteries（P>0.05）. Conclusion：CCTA can visualize the anatomical characteristics of CPF and measure relevant anatomical structures，thus providing useful information for clinical evaluation and therapeutic method selection for CPF.