Value of radiomics features from adrenal gland and periadrenal fat CT images predicting COVID-19 progression

BackgroundValue of radiomics features from the adrenal gland and periadrenal fat CT images for predicting disease progression in patients with COVID-19 has not been studied. MethodsA total of 1,245 patients (685 moderate and 560 severe patients) were enrolled in a retrospective study. We proposed 3D V-Net to segment adrenal glands in onset CT images automatically, and periadrenal fat was obtained using inflation operation around the adrenal gland. Next, we built a clinical model (CM), three radiomics models (adrenal gland model [AM], periadrenal fat model [PM], and fusion of adrenal gland and periadrenal fat model [FM]), and radiomics nomogram (RN) after radiomics features extracted to predict disease progression in patients with COVID-19. ResultsThe auto-segmentation framework yielded a dice value of 0.79 in the training set. CM, AM, PM, FM, and RN obtained AUCs of 0.712, 0.692, 0.763, 0.791, and 0.806, respectively in the training set. FM and RN had better predictive efficacy than CM (P < 0.0001) in the training set. RN showed that there was no significant difference in the validation set (mean absolute error [MAE] = 0.04) and test set (MAE = 0.075) between predictive and actual results. Decision curve analysis showed that if the threshold probability was more than 0.3 in the validation set or between 0.4 and 0.8 in the test set, it could gain more net benefits using RN than FM and CM. ConclusionRadiomics features extracted from the adrenal gland and periadrenal fat CT images may predict progression in patients with COVID-19. FundingThis study was funded by Science and Technology Foundation of Guizhou Province (QKHZC [2020]4Y002, QKHPTRC [2019]5803), the Guiyang Science and Technology Project (ZKXM [2020]4), Guizhou Science and Technology Department Key Lab. Project (QKF [2017]25), Beijing Medical and Health Foundation (YWJKJJHKYJJ-B20261CS) and the special fund for basic Research Operating Expenses of public welfare research institutes at the central level from Chinese Academy of Medical Sciences (2019PT320003).

Assisting Scalable Diagnosis Automatically via CT Images in the Combat against COVID-19

Introductory paragraphThe pandemic of coronavirus Disease 2019 (COVID-19) caused enormous loss of life globally. 1-3 Case identification is critical. The reference method is using real-time reverse transcription PCR (rRT-PCR) assays, with limitations that may curb its prompt large-scale application. COVID-19 manifests with chest computed tomography (CT) abnormalities, some even before the onset of symptoms. We tested the hypothesis that application of deep learning (DL) to the 3D CT images could help identify COVID-19 infections. Using the data from 920 COVID-19 and 1,073 non-COVID-19 pneumonia patients, we developed a modified DenseNet-264 model, COVIDNet, to classify CT images to either class. When tested on an independent set of 233 COVID-19 and 289 non-COVID-19 patients. COVIDNet achieved an accuracy rate of 94.3% and an area under the curve (AUC) of 0.98. Application of DL to CT images may improve both the efficiency and capacity of case detection and long-term surveillance.

The value of ultraGlarge pitch Turbo Flash scan mode in the diagnosis of tracheal foreign body in infants / 实用放射学杂志

Objective To explore the value of ultra-large pitch Turbo Flash scan mode in the diagnosis of tracheal foreign body in infants.Methods The imaging data of 60 infants with foreign body in trachea confirmed by bronchus endoscopy were analyzed retrospectively. The 60 infants were equally divided into 2 groups according to the scanning time.For group A,the routine scan with the mode of CARE Dose 4D/CARE kV and pitch as 1.9 was performed.For group B,the scan with ultra-large pitch Turbo Flash model was performed.The scanning time,volume CT dose index (CTDIvol)and dose length product (DLP)of each patient were recorded in both groups and statistically analyzed.Results The scanning time,DLP and CTDIvol of group A and group B were statistically significant.CTDIvol and DLP of group B were significantly lower than those of group A (P＜0.05).The diagnostic accuracy of group A and B were 100%(30/30),respectively (P＞0.05).The foreign body display of group A and B were 100% (30/30),respectively (P＞0.05).Conclusion Ultra-large pitch Turbo Flash can be used to detect tracheal foreign body in infants.It can significantly reduce radiation dose,shorten examination time and obtain satisfactory image quality.

Feasibility of ultra-large pitch Turbo Flash scan mode in chest scan in preschool children without sedatives / 中国医学影像技术

Objective To investigate the feasibility of chest examination using ultra-large pitch Turbo Flash in Force CT in preschool children without sedative.Methods A total of 90 preschool children evaluated as nervous or frightened were equally divided into 3 groups according to the scanning time.For group A,the routine scan with the mode of CARE Dose 4D/CARE kV was performed,and the sedative was used.For group B,the scan with ultra-large pitch Turbo Flash model and pitch as 3.0 was performed,and the sedative was used.For group C,the same scan mode as group B was performed but without sedative.The scanning time,radiation dose,image quality and the diagnostic efficiency were compared among 3 groups.Results There were no significant differences of the CT values of the aorta root,spinal posterior muscles and subcutaneous fat,the noise of the aorta root,SNR and CNR among 3 groups (all P＞0.05).Moreover,no significant differences of the subjective score of image quality in pulmonary window and mediastinum window images were found among 3 groups (both P＞0.05).The scanning time and radiation dose indexes (CT dose index volume [CTDIvo1],doselength product [DLP],effective dose [ED]) of group A were significantly higher than those of group B and group C (all P ＜0.05),while there were no significant differences between group B and group C (all P＞0.05).There were no significant differences between the CT diagnosis and clinical diagnosis results in all 3 groups (all P＞0.05).Conclusion It can shorten the scanning time and decrease the radiation dose by using the mode of ultra-large pitch Turbo Flash.And the satisfactory image quality can be obtained without sedative for nervous or frightened preschool children.

The diagnostic value of dual energy virtual non-contrast images of dual-source CT in the diagnosis of com-mon benign liver diseases / 实用医学杂志

Objective To investigate the diagnostic value and limitations of dual-energy virtual non-con-trast images of dual-source CT in common benign liver diseases. Methods Dual-source CT was performed on 226 upper abdomen pathogenesis patients. The conventional non-contrast (CNC) scan was performed with single-energy mode, the arterial phase and portal phase scans were performed with dual-energy mode. The virtual non-contrast (VNC) images were derived from the portal data using liver virtual non-contrast software. 117 patients with common benign liver diseases were retrospectively analyzed in CNC and VNC. The lesion detectability, effective radiation doses for single-energy mode and dual-energy mode were compared. Results Among 117 patients, there were 28 (73.6%) hemangiomas, 58 (85.3%) calcifications or stones in VNC, but the hemangiomas, calcifications or stones in CNC were 37 (97.3%) and 68 (100%), respectively. The hemangiomas, calcifications or stones in VNC and CNC were significantly different (P 0.05). The CTDIvol, DLP and ED of dual-energy mode were obviously lower than those of single-energy mode (P < 0.05). Conclusion The detection of hemangiomas, calcifications or stones on VNC images is lower than CNC images. There is no difference in detecting cyst and hepatic steatosis. In addition, radiation dose will be reduced due to adopting VNC.VNC has potential clinical application value.

A comparative study of diffusion tensor imaging parameters and pathologic changes in rabbit with acute spinal cord injury / 实用医学杂志

Objective To make spinal cor injury model of rabbit in order to investigate the feasibility and accuracy of diffusion tensor imaging in diagnosis of early ASCI. Methods In 30 Chinese rabbits ,24 rabbits were randomly selected as the experimental group and the other 6 as the control group. Allen′s technique were used to make moderateacute spinal cord injury in the experimental group. In the control group ,the operation only exposed the spinal membrane ,wihthout damage on the spinal cord. All rabbits were performed in routine MRI , DTI ,diffusion tensor tractography and post-processing. After the MRI scan ,the rabbit spinal cord was removed to have pathological examination at 1 ,3 ,5 ,7 days. Results The number of inflammatory cells and spinal motor neurons were closely correlated with FA values and ADC values. DTT images showed the spinal cord defects, curling and breaking. Conclusion The parameters of DTI (FA ,ADC) can reflect the pathological changes of acute spinal cord injury in early stage ,and therefore may be used as an routine evaluation method for clinical acute spinal cord injury.

Value of two left atrium and pulmonary vein stereoscopic imaging reconstruction methods on guiding radiofrequency ablation for atrial fibrillation / 中华心血管病杂志

Objective@#To compare the value of two 3D imaging reconstruction methods for left atria and pulmonary vein on guiding the catheter ablation for atrial fibrillation (AF).@*Methods@#From January 2014 to January 2017, a total of 100 drug refractory paroxysmal AF patients were divided into left atria direct angiography group (n=50), and indirect angiography group (n=50). 3D CARTO system was applied for mapping and guiding the ablation procedure. Patients assigned to direct angiography group were treated as follows: intraoperative puncture of atrial septum, inject contrast agent directly into the left atrium, conduct left atrial and pulmonary venous rotation angiography, reconstruct three-dimensional image, integrate the image into real-time X-ray system to facilitate circumferential pulmonary vein isolation. Patients assigned into the indirect angiography group were treated as follows: inject contrast agent through the right ventricle, conduct delayed rotation angiography of the left atria and pulmonary vein to guide circumferential pulmonary vein fixation and ablation. The left atrial and pulmonary venous image acquisition, the operation and X-ray exposure time, the success rate and the incidence of complication of the two groups were compared. The patients were followed up for 3-6 months.@*Results@#General clinical characteristics of the two groups were similar(all P>0.05). Ablation was successful in all 100 patients. The operation time[(112.0±21.4)min vs. (134.0±24.3)min]and X-ray exposure time((10.7±4.7)min vs. (15.8±5.2)min)were significantly lower in direct angiography group than in indirect angiography group (both P<0.01). There was no significant difference between the two groups in the immediate (86%(43/50) vs. 82%(41/50), P=0.59) and short-term (76%(38/50) vs. 72%(36/50), P=0.65) success rate and complication rate (1 aneurysm in the direct angiography group, 1 pericardial tamponade in the indirect angiography group). In-hospital mortality was zero percent.@*Conclusion@#It is safe and effective method to guide the radiofrequency catheter ablation of paroxysmal atrial fibrillation by reconstruction 3D image of left atrium and pulmonary vein. Compared with indirect angiography group, direct angiography group can improve the imaging quality of left atrium and pulmonary vein, decrease the X-ray exposure time of the ablation procedure.

Quantitative analysis of T2 value of shoulder joint cartilage in healthy young adult using T2 mapping / 中国医学影像技术

Objective To investigate the feasibility of T2 mapping in evaluating the composition of shoulder cartilage,and to quantitatively analyze T2 values of articular cartilage in healthy young volunteers.Methods Oblique coronal T2 mapping imaging with 8 echo was performed in bilateral shoulder of 16 young healthy volunteers.The pseudo-color map was obtained with post-processing.The shoulder joint cartilage was equally divided into the external,central and internal zones,and T2 values were measured quantitatively.T2 values in the external,central and internal zones were analyzed and compared.T2 values of cartilage between male and female volunteers as well as between left and right sides were analyzed.Resuits T2 values in the external,central and internal zones of cartilage were (38.67 ± 2.82)ms,(38.41 ± 2.52)ms and (36.49± 1.80)ms,respectively.The overall difference was statistically significant (F=7.789,P=0.001).T2 values in the external and central zones of cartilage were larger than those in the internal zone (both P＜0.05).T2 values of cartilagehad no significant differences between the left and right sides in the external,central and internal zones (all P＞0.05).There was significant difference of T2 value in the central zone (P＜0.05),while no significant difference of T2 value in the external and internal zones between different genders was found (both P＞0.05).Conclusion T2 mapping imaging can be used to evaluate the composition of shoulder cartilage changes.

Application of low kilovoltage combined with sinogram affirmed iterative reconstruction in assessment of calcified plaque in coronary artery / 实用医学杂志

Objective To investigate the performance of dual source CT scanning combined with low-tube-voltage iterative reconstruction (SAFIRE) for demonstrating coronary artery calcium plaques. Methods 70 patients with clinically suspected coronary atherosclerosis and with normal BMI received SAFIRE-3 or filtered back projection (FBP) for reconstruction after undergoing CT scans with tube voltage range of 100 kV. The CT images (average CT values, noise, SNR, and CNR) and subjective scores (number of calcium plaque, calcium plaque adjacent artifacts, and image quality) were compared between the two groups. Results The average CT value of the aortic root did not differ significantly between the two procedures for reconstruction (P > 0.05). Ob jective evaluation of the images (noise, SNR, and CNR) between the two groups was statistically significant (P < 0.05 for all comparisons), so was image subjective rating (number of calcium plaque and rate of calcium plaque edge)(P < 0.05 for all comparisons). SAFIRE-3 reconstruction was markedly superior to FBP reconstruc-tion. Conclusions Low kilovoltage combined with reconstruction of SAFIRE-3 can reduce calcium plaque adja-cent artifacts and enhance quality of images , which is better than FBP in displaying the morphology and adjacent conditions of calcified plaque; therefore it is worth popularizing.

Based on the teeth in vitro skull specimen to investigate CARE kV CT scan technology of decreasing radiation dose / 实用医学杂志

Objective Based on the teeth in vitro skull specimen to investigate the feasibility and accuracy of CARE kV CT scan for reducing radiation dose. Methods Of eight fixed and preserved skull teeth were scanned repeatedly in groups of A, B, C. In expose factors of 100 kVp/150 mAs in conventional scanning of group A, open CARE Dose 4D scan of group B and CARE kV scan of group C. We assessed the radiation dose in the group A, B and C, the average CT values of the images, noise, SNR, CNR and subjective ratings. Results Three groups of actual scan tube current, tube voltage and radiation dose were statistically significant (P 0.05). Conclusion CARE kV technology based on the use specimens tooth can reduce the radiation dose, protect image quality, and be consistent to the reports of previous researches.

Parameter optimization of low-dose Flash CT scan of the chest:an animal experiment / 实用放射学杂志

Objective To explore the optimized scanning parameters of low-dose un-enhanced chest CT with sinogram affirmed iterative reconstruction (SAFIRE).Methods Eleven healthy adult domestic dogs underwent chest scanning of 120 kV,100 kV,80 kV,70 kV with a fixed tube current of 65 mA and halved tube current of 32 mA with a fixed tube voltage of 100 kV.The data were reconstructed with filtered back projection (FBP)and SAFIRE (strength grade 3)respectively to obtain ten groups of images.The regular dose (120 kV/65 mA ) combining with FBP reconstruction was as normal control group,and other groups as experimental groups.CT dose index (CTDI), dose length product (DLP),and effective dose (ED)at different dose were compared,and average CT value,noise,signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR)and image quality score of ten groups of images were comparatively analyzed.Results No significant differences were found in average CT value for lung tissue,the superior vena cava,the aortic arch,and spinal muscles among ten groups (P >0.05),except adipose tissue (P 3),and the radiation dose of this group decreased by 81.33%.Conclusion Reconstructed with SAFRIE technology,the image quality of 100 kV/65 mA scanning of chest CT is similar to that of routinely reconstructed images in regular dose,while the image quality of 70 kV/65 mA scanning can not only meet the requirements of diagnosis but also obviously reduce radiation dose.

Diagnostic value of matrix gamma carboxy glutamic acid protein for coronary heart disease / 国际检验医学杂志

Objective To investigate the diagnostic value of matrix gamma carboxy glutamic acid protein(MGP) for coronary heart disease(CHD) .Methods Enzyme linked immunosorbent assay was performed for the detection of serum MGP level in health‐y subjects and CHD patients with different coronary artery calcium score(CACS) .Receiver operating characteristic(ROC) curve was used to analyze the diagnostic value of MGP for CHD .Results Between CHD patients and healthy subjects ,and CHD patients with different CACS ,the difference of serum MGP level was significant ,and serum MGP level was positively correlated with CACS (P<0 .05) .ROC curve of showed that the area under ROC curve was 0 .667 ,the diagnostic threshold was 70 .69 pg/mL ,the diag‐nostic sensitivity was 58 .80% ,the specificity was 83 .70% and the Youden index was 0 .425 .Conclusion CHD patients might be with abnormal serum MGP level ,which could be positively correlated with CACS .MGP might be with significant value for the diag‐nosis of CHD ,could be useful for the clinical prevention and early diagnosis of CHD .

Mutation analysis of the TRAPPC2 gene in a Chinese family with X-linked spondyloepiphyseal dysplasia tarda / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify potential mutation of TRAPPC2 gene in a Chinese family affected with X-linked spondyloepiphyseal dysplasia tarda (X-SEDL), and explore its underlying molecular mechanism.</p><p><b>METHODS</b>Peripheral blood samples were collected from 32 members of the family and 50 healthy adults to extract genomic DNA. DNA sequences of exons 3 to 6 and their exon/intron boundaries were amplified with PCR amplification. Direct bi-directional sequencing analysis was performed on the PCR products. The sequences were aligned to the reference sequences from the GenBank to determine mutation site and type.</p><p><b>RESULTS</b>A nucleotide substitution of the splice-donor in TRAPPC2 intron 3, c.93+5G>A, was detected in the proband, but no sequence change was detected in TRAPPC2 exons 3 to 6. All of the 6 male patients and 8 female carriers from the family were detected to have carried this mutation. The same mutation was not found in the remaining 18 family members with a normal phenotype and 50 healthy controls.</p><p><b>CONCLUSION</b>We have detected a c.93+5G>A mutation in the TRAPPC2 gene in a Chinese family affected with X-SEDL. Our results have expanded the spectrum of TRAPPC2 mutations and is helpful for presymptomatic and prenatal diagnoses of this disease.</p>

Normal kidney data of adult Guizhou miniature pigs measured by multislice spiral CT in vivo / 中国实验动物学报

Objective To establish normal kidney data by measuring the diameter and volume of the kidneys in a -dult Guizhou miniature pig.Methods Twelve healthy adult Guizhou miniature pigs (male 6, female 6) were used in this study.The kidneys were scanned by using Siemens dual source CT , and the raw data were used for multiplanar reconstruc-tion (MPR) and volume reconstruction (VR) using the software Aquarius iNtuition 4.4.The anteroposterior and left to right dimensions of both kidneys were measured at the median transverse plane of the organ , and the long and short diame-ters of both kidneys were measured at the maximum coronal section of the organ .The volume of both kidneys and miniature pig itself, the ratio of long to short diameters of both kidneys , and the relationship between the ratio of long to short diame-ter and the kidney were calculated .The correlation between the length dimension , length diameter ratio and the volume of the kidney was analyzed , and the correlation between volume of the kidney and miniature pig was analyzed as well .P<0.05 was set as statistically significant .Results The dimensions of anteroposterior , left to right, long and short diameters of left kidney were 40.40 ±1.67 mm, 27.47 ±1.40 mm, 80.36 ±2.74 mm and 31.79 ±1.99 mm, respectively.The vol-ume of left kidney was 52.78 ±2.25 cm3 , and the ratio of long to short diameter of the left kidney was 2.42 to 2.71:1. The dimension of anteroposterior , left to right, long and short diameters of the right kidney were 40.95 ±1.43 mm, 26.90 ±0.65 mm,79.03 ±2.38 mm and 32.04 ±2.34 mm, respectively .The volume of right kidney was 51.91 ±2.25 cm3 , and the ratio of long to short diameter of the right kidney was 2.33 to 2.77:1.There were highly positive and significant correlations between the long diameter and the kidney volume (rleft =0.92, P<0.05;rright =0.88, P<0.05) as well as between the kidney volume and the miniature pig (rleft =0.96, P<0.05;rright=0.98, P<0.05), while the ratio of long to short diameter of the kidney was negatively related to the volume of the miniature pig ( rleft =-0.51, P<0.05;rright=-0.67, P<0.05).Conclusions Multislice spiral CT and its post-processing software can accurately measure various data of the kidneys of Guizhou miniature pig in vivo , providing normal reference of the animal model for the research of hu -man kidney diseases .

A comparative study of MRI and ultrasonic cardiography in morphology and blood flow of cavopulmonary anastomosis for patients with bidirectional Glenn shunt / 中华放射学杂志

Objective To investigate the difference of morphology and blood flow of cavopulmonary anastomosis by MRI and that by ultrasonic cardiography (UCG) in patients with bidirectional Glenn shunt (BGS).Methods Phase-contrast MRI (PC-MRI) and contrast enhanced MRI (CE-MRI) were performed for superior vena cava ( SVC ) and inferior vena cava (IVC) in 22 patients with BGS on 3.0 T MR scanner.PC-MRI was used for measuring blood flow and CE-MRI for illustrating morphology.The width,peak flow velocity and gradient pressure of cavopulmonary anastomosis were calculated by using Report Card software.The similar data of UCG was collected.The parameters by MRI and that by UCG were compared statistically by t test and Pearson correlation.Results Based on the MRI data,the blood flow of SVC [ ( 1.002 ±0.208) L/min ] was significantly lower than that of IVC [ ( 1.794 ± 0.392 ) L/min ] ( t =- 15.148,P ＜0.01 ),while the regurgitation fraction of SVC [ (26.54 ± 12.82)％ ] was significantly higher than that ofIVC [ ( 17.44 ± 10.17)％ ] (t =11.060,P ＜0.01 ).The morphology displayed with MRI angiography couldnot be detected with UCG.The width of cavopulmonary anastomosis measured by MRI [ (12.46 ±3.43 ) mm ] was significantly higher than that of UCG[ ( 11.04 ± 2.63 ) mm] ( t =4.048,P ＜ 0.01 ),while the peak flow velocity of cavopulmonary anastomosis measured by MRI [ (47.77 ± 10.44) cm/s] was significantly lower than that of UCG [ (52.19 + 9.63) cm/s] ( t =- 2.237,P ＜ 0.05 ).No significant difference was found in gradient pressure of cavopulmonary anastomosis between the values by MRI [(0.95+0.42) mm Hg(1 mm Hg =0.133 kPa)] and that by UCG [(1.12+0.38)mm Hg] (t=2.010,P ＞ 0.05).The width,peak flow velocity and gradient pressure of cavopulmonary anastomosis by MRI were closely correlated with those by UCG (r =0.858,0.489,0.427,all P＜ 0.05 ).Conclusions A good correlation is found in the width,peak flow velocity,and gradient pressure of the cavopulmonary anastomosis obtained by 3.0 T MRI and UCG.MRI is more useful tool to display the width and abnormal morphology of cavopulmonary anastomosis than UCG.

Multi-slice spiral CT in the diagnosis of congenital heart diseases associated with tracheobronchial stenosis in children / 中华放射学杂志

Objective To explore the diagnostic value of post processing techniques of MSCT for diagnosing congenital heart disease associated with tracheobronchial stenosis in children. Methods Thirty four patients with congenital heart disease complicated by tracheobronchial stenosis were evaluated with MSCT. MPR, CPR, MinIP and VR were performed to show the tracheobronchial morphology. Findings in 43 segments of 32 cases were compared with the findings of surgical operation. Mann-Whitney test was employed to assess the significance of measurement between the post processing techniques and the operation. Results The lenghth of stenotic segments were variable seen at operation, with values between 4-39 mm in trachea, 4-33 mm in main bronchi and 3-12 mm in lobe bronchi, respectively. The biggest difference between the measurement of operation and MSCT was 4 mm (3 segments). Other differences ofstenotic segments were within 3 mm. Six segments exhibitee mild, 16 moderate and 21 severe stenosis at surgery. By contrast, five segments exhibited mild, 17 moderate and 21 severe stenosis by MPR or CPR,2 mild,9 moderate and 32 severe stenosis by MinIP and 4 mild, 11 moderate and 28 sever stenosis by VR,respectively. There was no significant difference in measuring the degree of tracheobronchial stenosis between MPR or CPR, VR and the surgery (Z =-0. 105,- 1. 479;P ＞0.05), while MinIP frequently overrated the degree of stenosis compared with the measurement at surgery (Z=-2.484,P =0. 013). Conclusion The integrated three dimensional reformations of MSCT scan can accurately evaluate the degree and extent of congenital heart disease associated with tracheobronchial stenosis in children and provide valuable information for clinical management.

Coronary Angiography with 16-slice Spiral CT:a Study of Technique and Clinical Application / 实用放射学杂志

Objective To evaluate the main scanning technique and clinical value of 16-slice spiral CT coronary angiography(CTCA).Methods Plain and enhanced imaging were performed by retrospective ECG gating in 76 patients,including 65 cases suspected coronary artery disease,8 cases of coronary stent and 3 cases of coronary bypass graft.Post-processing was conducted with VesselView soft package,in which MPR,MIP,VRT and section plane of conoray artery were made in all cases,among them 35 cases underwent selective coronary angiography(SCA) as a comparision.These main segments(vessel diameter≥2 mm) in CTCA were compared with SCA,and≥50% reduction of vessel diameter was defined as significant disease.Results 85.1% of the coronary segments in CTCA were accessible and could accurately displaye the patency of the coronary arteries and the pathological changes in vessel walls.In comparison with SCA,the sensitivity and specificity were 86.5% and 95.1% respectively. When 46 coronary artery segments judged unevaluable were included in the analysis,the sensitivity was 78.0%(32/41).Conclusion 16-slice CTCA can display long segment of coronary artery and assess coronary artery disease with high accuracy,which has highly clinical value.