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Objective To evaluate the value of dual-source CT angiography for evaluating the degree of coronary stenosis. Methods A total of 110 patients with a high likelihood of coronary stenosis identified by dual-source CT angiography or conventional coronary angiography were enrolled. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of dual-source CT angiography for diagnosis of coronary stenosis were evaluated with conventional coronary angiography as a gold standard. The agreement between dual-source CT angiography and conventional coronary angiography for evaluation of coronary stenosis was evaluated using Kappa statistic. Results A total of 1 401 coronary artery segments from 110 patients were displayed on conventional coronary angiography, while 1 382 segments were successfully visualized in dual-source CT angiography (98.64%). The sensitivity, specificity, positive predictive value and negative predictive value of dual-source CT angiography were 97.9%, 97.3%, 90.4% and 99.4% for diagnosis of coronary stenosis, and there was high consistence between dual-source CT angiography and conventional coronary angiography for grading coronary stenosis (Kappa statistic = 0.87, U = 58.36, P < 0.01). In addition, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of dual-source CT angiography were 94.7%, 96.8%, 83.7%, 99.0% and 96.5% for grading stenosis of coronary artery segments. Conclusion Dual-source CT angiography is accurate and reliable for diagnosis of coronary stenosis, which may be a non-invasive tool for assessment of coronary stenosis.
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Objective:To evaluate the application value of dual-source CT in detecting the components of urinary calculi in children.Methods:A retrospective analysis of 433 children treated for urinary calculi in the Urological Center, People′s Hospital of Xinjiang Uygur Autonomous Region from March 2018 to January 2021 was performed in parallel with dual-source CT examination. The data was processed by the post-processing workstation and the stone composition was analyzed. The analysis results were compared with the results of infrared spectroscopy, and the accuracy of dual-source CT analysis of stones and the predictive value of dual-source CT various measurement indexes for the types of stones were compared. The measurement data were expressed as mean±standard deviation ( Mean± SD), and the comparison of the measurement indexes of each stone type [average CT value, dual energy difference, dual energy ratio and dual energy index (DEI)] were compared by One-way Anova analysis of variance. Draw receiver operator characteristic curve and calculate the area under the curve (AVC), then evaluate the diagnostic efficacy of each index. Results:Dual-source CT detected 282 calcium oxalate stones, 238 calcium phosphate stones, 39 uric acid stones and 7 cystine stones. Compared with the results of infrared spectroscopy, the accuracy rates of dual-source for calcium oxalate stones and hydroxyapatite stones were 84.2% and 81.8%, respectively. Both uric acid stones and cystine stones were accurately detected. In addition, dual energy difference, dual energy ratio, and DEI have reliable predictive value for calcium oxalate stones and calcium phosphate stones, especially dual energy ratio and DEI, both AUC>0.75.Conclusion:Using advanced post-processing analysis methods, dual-source CT can reliably analyze the components of children′s urinary tract stones, and provide a reference for choosing personalized treatment plans.
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Objective To evaluate the feasibility of dual-source low-dose computed tomography (CT) of the paranasal sinus in children, with acquisition at an ultra-low tube voltage (70 kVp) combined with the Flash scan. Methods CT scans of the paranasal sinus were performed on 80 pediatric patients who were divided into two groups according to different protocols (70 kVp protocol with Flash scan mode and the iterative reconstruction, pitch 3, the experimental group (group A), n = 40; 80 kVp protocol with conventional spiral mode, pitch 1.5, control group (group B), n = 40). For each examination, the CT dose index (CTDIvol), dose-length product (DLP) and effective dose (ED) were estimated. The image noise, signal-to-noise ratio (SNR) and overall subjective diagnostic image quality were also evaluated. Results The images of these two groups were all satisfied for the clinical diagnosis. For radiation dose, the CTDIvol (mGy), DLP (mGycm) and ED (mSv) values of the 70 kVp protocol were significantly lower than those of the 80 kVp protocol [CTDIvol: 0.39 ± 0.004 vs1.57 ± 0.009 mGy, P < 0.001; DLP: 6.31 ± 0.52 vs 19.88 ± 2.01 mGycm, P < 0.001; ED: 0.024 ± 0.005 vs 0.079 ± 0.016 mSv, P < 0.001. Compared with those of the 80-kVp protocol, the image noise and the SNRbone increased, the SNRsoft-tissue decreased. There was no statistical difference in the subjective scores of the two groups of image quality by the two physicians (P > 0.05). Conclusion When diagnosing the paranasal sinus in children, an ultralow tube voltage (70 kVp) combined with the Flash scan technique can reduce the radiation dose significantly while maintaining diagnostic image quality with clinically acceptable image noise.
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Objective To assess the influence of different time sampling modes on perfusion parameters and radiation dose of whole-brain computed tomography perfusion imaging (CTP), and to formulate an optimized scanning protocol for clinical diagnosis requirements. Methods Forty-seven consecutive patients, who underwent cerebral CTP scanning in our hospital between Nov. 2016 and Jun. 2017, were included in this study. Nineteen of them had acute ischemic stroke (AIS) and 28 had AIS symptoms, but no lesions were found by computed tomography or CTP. According to the time-attenuation curve, four scanning protocols were obtained: standard control group (group 1), sampling interval of 3 s (group 2), sampling interval of 3 s in pre-ascending and pro-descending period, and sampling interval of 1.5 s in the intermediate period (group 3), and smapling interval of 1.5 s between the peak of artery and vein and other sampling interval of 3 s (group 4). The perfusion parameters of all subjects were quantitatively measured. Subjective image quality was analyzed and radiation dose was calculated. Results In AIS and non-AIS groups, a total of 10 region of interests were placed in the ischemic area and contralateral brain parenchyma of each patient, and the total numbers of data points of perfusion parameters were 190 and 280, respectively. There were significant differences in blood flow, blood volume and mean transit time (MTT) between the AIS group and non-AIS group (all P0.01). However, inter-group analysis showed that there were no significant differences in the above perfusion parameters between group 3 and group 1 in both the AIS group and non-AIS group (all P0.05). Bland-Altman consistency analysis showed that group 3 and group 1 had good consistency of blood flow, blood volume and MTT in both the AIS group and non-AIS group. Compared with group 1 (standard control group), group 3 had better subjective score and lower radiation dose. Based on the sampling mode of group 3, 2 recommended scanning protocols were established and validated. The perfusion parameters of the 2 recommended scanning protocols were well correlated with those of group 1 in AIS patients and non-AIS patients (all P0.01). Conclusion The scanning protocol, in which sampling interval is 3 s in pre-ascending and pro-descending period and 1.5 s in intermediate period, is in good agreement with the standard scanning mode, and can reduce radiation dose. It may be a whole-brain CTP scanning protocol for the clinical settings.
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Objective Dual-source CT(DSCT) energy imaging was used to analyze the difference of energy spectrum pa-rameters and energy spectrum curves between mediastinal metastatic lymph nodes and non-metastatic lymph nodes in non-small cell lung cancer(NSCLC). The relationship between DSCT standardized iodine concentration and energy spectrum curve with medias-tinal lymph node metastasis was discussed. Methods A total of 113 patients with NSCLC underwent DSCT energy imaging scans. Io-dine images were obtained at the processing workstation. The normalized iodine concentrations of all mediastinal lymph nodes and en-ergy spectrum curves at different energy levels were measured. According to the pathological results,the patients were divided into lymph node metastasis group and non-lymph node metastasis group. The normalized iodine concentration and energy spectrum curve slope of the two groups were analyzed by t-test. The best threshold of standardized working iodine concentration was calculated by re-ceiver operating characteristic curve(ROC)to diagnose the mediastinal lymph node metastasis of NSCLC. Results There was a sig-nificant difference in the normalized iodine concentration between the two groups of mediastinal lymph nodes in NSCLC(P<0. 05);The ROC curve was used to calculate the standardized iodine concentration for the diagnosis of NSCLC. The optimal threshold for lymph node metastasis was 52. 45% ;The energy spectrum curve of mediastinal lymph nodes in NSCLC was gradually decreasing. There was a significant difference between the two groups in the range of 40~110 keV interval(P<0. 05). Conclusion The quanti-tative analysis of DSCT energy imaging parameters is of great significance in the diagnosis of mediastinal lymph node metastasis in NSCLC. It can be used as an important index for preoperative judgment of lymph node metastasis in NSCLC.
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Objective Exploration of the application value of the third-generation dual source CT low tube voltage (70 kVp) scanning combined with advanced modeling iterative reconstruction (ADMIRE) technique in children with adenoid examination. Methods CT scans were performed in patients with clinically suspected adenoid hypertrophy. They were divided into two groups according to the time of treatment. Group A (40 cases) : low tube voltage (70 kVp) scan, reference tube current 163 mAs, reconstruction with ADMIER, Intensity 3; Group B (40 cases) : conventional 100 kVp, reference tube current 163 mAs, conventional (filtered back-projection, FBP) reconstruction;rest of the scanning parameters remained unchanged. The subjective scores and objective quality indicators of the images (CT value, image noise, signal noise ratio (SNR) , contrast noise ratio (CNR)) and radiation dose of the two groups were compared. Results The difference of radiation dose between group A and group B was statistically significant (P < 0.05). The radiation dose of group A was lower than that of group B by 77.58％.Compared with group B, the image noise of group A increased by 0.002％; the SNR decreased by 0.01％; CNR increased by 0.03％; there was no significant difference in objective quality evaluation index and subjective score between two groups in the image quality (P> 0.05). Conclusion The third-generation dual-source CT low-tube voltage (70 kVp) combined with ADMIRE reconstruction technique for children with adenoid scan can effectively reduce the radiation dose while ensuring image quality.
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OBJECTIVE: To compare image quality and radiation dose of high-pitch dual-source spiral cardiothoracic computed tomography (CT) between non-electrocardiography (ECG)-synchronized and prospectively ECG-triggered data acquisitions in young children with congenital heart disease. MATERIALS AND METHODS: Eighty-six children (≤ 3 years) with congenital heart disease who underwent high-pitch dual-source spiral cardiothoracic CT were included in this retrospective study. They were divided into two groups (n = 43 for each; group 1 with non-ECG-synchronization and group 2 with prospective ECG triggering). Patient-related parameters, radiation dose, and image quality were compared between the two groups. RESULTS: There were no significant differences in patient-related parameters including age, cross-sectional area, body density, and water-equivalent area between the two groups (p > 0.05). Regarding radiation dose parameters, only volume CT dose index values were significantly different between group 1 (1.13 ± 0.09 mGy) and group 2 (1.07 ± 0.12 mGy, p 0.05). CONCLUSION: In high-pitch dual-source spiral pediatric cardiothoracic CT, additional ECG triggering does not substantially reduce motion artifacts in young children with congenital heart disease.
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Child , Humans , Aorta , Artifacts , Cone-Beam Computed Tomography , Coronary Vessels , Diaphragm , Electrocardiography , Heart Defects, Congenital , Lung , Noise , Prospective Studies , Retrospective Studies , Signal-To-Noise Ratio , Thoracic WallABSTRACT
Obective: To evaluate and compare the diagnostic values between myocardial perfusion imaging (MPD and dual source CT coronary angiography (DS-CTCA) in coronary artery stenosis in the diabetic patients with coronary heart disease (CHD), and to elucidate the clinical application values of MPI combined with DS-CTA in the diabetic patients with CHD. Methods: A total of 52 diabetic patients with CHD underwent the examinations of MPI and DS-CTCA were selected. The degrees of coronary artery stenosis of branches of coronary artery were compared between MPI examination and DS-CTCA examination, including left main coronary artery (LM), left anterior descending coronary artery (LAD), left circumflex branch (LCX) and right coronary artery (RCA). Based on the coronary angiography (CAG) regarded as the golden standard, the specificity, sensitivity and accuracy of each imaging examination method were compared; the specificities, sensitivities and accuracies of parallel diagnosis and serial diagnosis of two kinds of methods were also compared. Results: The stenosis degrees of LM and LAD were no different between MPI examination and DS-CTCA examination (P>0.05), but the stenosis degrees of LCX and RCA were different between two imaging examination methods (P<0.05). Compared with MPI examination, the sensitivity of DS-CTCA examination in the diabetic patients with CHD was decreased (71.0% vs 90.1%), and the difference was significant (P=0.035); the specificity of DS-CTCA examination in the diabetic patients with CHD was increased (85.7% vs 58.4%), and the difference was significant (P=0.027); but the accuracies of two examinations in the diabetic patients with CHD were no different (76.4%-us 78.4%) (P=0.062). Compared with parallel diagnosis, the specificity and accuracy of serial diagnosis were increased (93.5% vs 33.8%, P = 0.001; 94.7% vs 71.2%, P = 0.030); but the sensitivities had no difference (95.4% vs 93.1%, P= 0.074). Conclusion: The diagnostic accuracy of evaluating the degree of coronary artery stenosis in the diabetic patients with CHD is not different between DS-CTCA examination and MPI examination. And the serial diagnosis of two examination methods can improve the diagnostic accuracy.
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Objective To evaluate the application of high-pitch dual-source CT with prospective ECG gated double scan mode (Double Flash) in postoperative follow-up of coronary artery bypass grafting (CABG).Methods Sixty-one patients undergone CABG and received coronary CT angiography (CCTA) from Apr.2012 to Dec.2014 were enrolled in present study.The patients were randomly divided into two groups according to scanning mode:group A (Double Flash mode,30 cases) and group B (retrospective ECG gated spiral mode,31cases).Evaluation parameters included volumetric CT dose index (CTDIvol) and effective radiation dose (ED).All the coronary segments were evaluated with double blind method by two independent observers according to the image quality (IQ) on 4-point scale (1:excellent to 4:non-diagnostic).Results There were 139 coronary artery bypass grafts in 2 groups.Group A had 69 grafts,including 25 artery grafts and 44 venous grafts.Group B had 70 grafts,including 29 grafts and 41 venous grafts.No significant difference was found in IQ.between the two groups for all coronary segments (1.22 ± 0.57 vs.1.21 ± 0.61,P=0.975).ED (4.34 ± 1.88 vs.17.07 ± 2.13mSv,P＜0.001) and CTDIvol (5.70 ± 2.36 vs.40.95 ± 3.12mGy,P＜0.001) were significantly lower in group A than in group B.Conclusion Double Flash spiral protocol of dual-source CCTA can acquire good image quality with reduced radiation dose during assessment of CABG patency,and might have potential value in the follow-up of CABG patency.
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Objective:To evaluate the association between the level of plasma proprotein convertase subtilisin/Kexin 9 (PCSK9) with incidence and severity of calcified aortic valve disease(CAVD).Methods:We prospectively recruited 120 CAVD patients with at least increased echo density and 40 control patients by transthoracic echocardiography.All patients were grouped by CT quantitative scoring system:aortic valve calcification (AVC)1,2,3 and 4.Calcium score of aortic valve were calculated.Total cholesterol (TC),low density lipoprotein cholesterol (LDL-C),high density lipoprotein cholesterol (HDL-C),triglyceride (TG), carrying lipoprotein A1 (apo A1) and apolipoprotein B (apo B),lipoprotein (a) {LP (a)} and hypersensitive C-reactive protein (hsCRP) were detected by biochemical analyzer.Plasma PCSK9 levels were measured by enzyme-linked immunosorbent assay.The re-lationship between AVC and plasma PCSK9 level,blood lipid,Apo A1,Apo B and hsCRP was analyzed.Results:The data indicated that Apo,B Lp(a) and LDL-C levels in AVC2-4 level was significantly higher than that of AVC1(P<0.05),while TG,APO,A1 HDL-C and hsCRP were not different significantly in the four groups.The levels of TC in group AVC3 and AVC4 were significantly higher than those in group AVC1(P<0.05).At the same time,the patients of grade AVC2-4 have higher level of plasma PCSK9 than patients of group AVC1(P<0.05).Correlation analysis was performed and aortic valve calcium score were significantly correlated with TC (r=0.248,P=0.026),LDL-C (r=0.222,P=0.048),Lp(a) (r=0.276,P=0.013),Apo A1(r=0.245,P=0.012),Apo B(r=0.212, P=0.019) and PCSK9(r=0.309,P=0.005) in all study subjects.PCSK9 was positively correlated with TC,LDL,LP (a),Apo A1, Apo,and no correlation with hsCRP (B).Conclusion:The level of PCSK9 in CAVD patients was significantly higher than that in control group.And there is an association of PCSK9 levels with the presence of CAVD,however.
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OBJECTIVE: To compare radiation doses between conventional and chest pain protocols using dual-source retrospectively electrocardiography (ECG)-gated cardiothoracic computed tomography (CT) in children and adults and assess the effect of tube current saturation on radiation dose reduction. MATERIALS AND METHODS: This study included 104 patients (16.6 ± 7.7 years, range 5–48 years) that were divided into two groups: those with and those without tube current saturation. The estimated radiation doses of retrospectively ECG-gated spiral cardiothoracic CT were compared between conventional, uniphasic, and biphasic chest pain protocols acquired with the same imaging parameters in the same patients by using paired t tests. Dose reduction percentages, patient ages, volume CT dose index values, and tube current time products per rotation were compared between the two groups by using unpaired t tests. A p value 0.05); the groups with tube current saturation showed significantly higher volume CT dose index values (p < 0.01) and tube current time product per rotation (p < 0.001) than the groups without tube current saturation in all protocols. CONCLUSION: The radiation dose of dual-source retrospectively ECG-gated spiral cardiothoracic CT can be reduced by approximately 15% by using the biphasic chest pain protocol instead of the conventional protocol in children and adults if radiation dose parameters are further optimized to avoid tube current saturation.
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Adult , Child , Humans , Chest Pain , Cone-Beam Computed Tomography , Electrocardiography , Methods , Retrospective Studies , ThoraxABSTRACT
Objective:To evaluate and compare the diagnostic values between myocardial perfusion imaging (MPI)and dual source CT coronary angiography(DS-CTCA)in coronary artery stenosis in the diabetic patients with coronary heart disease(CHD),and to elucidate the clinical application values of MPI combined with DS-CTA in the diabetic patients with CHD.Methods:A total of 52 diabetic patients with CHD underwent the examinations of MPI and DS-CTCA were selected.The degrees of coronary artery stenosis of branches of coronary artery were compared between MPI examination and DS-CTCA examination,including left main coronary artery(LM),left anterior descending coronary artery(LAD),left circumflex branch(LCX)and right coronary artery(RCA).Based on the coronary angiography(CAG)regarded as the golden standard,the specificity,sensitivity and accuracy of each imaging examination method were compared;the specificities,sensitivities and accuracies of parallel diagnosis and serial diagnosis of two kinds of methods were also compared.Results:The stenosis degrees of LM and LAD were no different between MPI examination and DS-CTCA examination(P>0.05),but the stenosis degrees of LCX and RCA were different between two imaging examination methods(P<0.05).Compared with MPI examination, the sensitivity of DS-CTCA examination in the diabetic patients with CHD was decreased(71.0%vs 90.1%),and the difference was significant(P=0.035);the specificity of DS-CTCA examination in the diabetic patients with CHD was increased(85.7%vs 58.4%),and the difference was significant(P=0.027);but the accuracies of two examinations in the diabetic patients with CHD were no different(76.4%vs 78.4%)(P=0.062).Compared with parallel diagnosis,the specificity and accuracy of serial diagnosis were increased(93.5% vs 33.8%,P=0.001;94.7%vs 71.2%,P = 0.030);but the sensitivities had no difference(95.4% vs 93.1%,P = 0.074). Conclusion:The diagnostic accuracy of evaluating the degree of coronary artery stenosis in the diabetic patients with CHD is not different between DS-CTCA examination and MPI examination. And the serial diagnosis of two examination methods can improve the diagnostic accuracy.
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Objective The objective of this study was to determine the lesion range between gastric cancer lesions and normal gastric wall,improve the early diagnosis of gastric cancer rate,distinguish between me-tastatic lymph nodes and non-metastatic lymph nodes,and accurate N staging by dual-source CT double-en-ergy enhanced scan parameters.Methods The dual energy enhanced scan of patients with preoperative gastric cancer was performed by Siemens Somatom Definition Flash dual-source CT.The collected data were analyzed by Syngo.Via software and reconstructed three-dimensionally to obtain the absolute iodine of gastric cancer,nor-mal gastric wall,metastatic lymph node and non-metastatic lymph node value,standardized iodine value and vir-tual single energy spectrum curve of the slope to combine with postoperative pathological results.The use of statis-tical methods was to determine the difference between the post-and preoperation.Results The absolute iodine values(IC)were(3.329±0.812)g/L in the gastric cancer lesion and(64.006±17.450)% for the standard io-dine values(NIC).The slope of the virtual single energy spectrum curve was-2.916±1.3227,IC(1.563±0.708)g/L in the normal gastric wall.The NIC were(37.122±16.267)%and-1.621±1.4028 for the slope of the virtual single energy spectrum curve.They were significantly statistical difference(P<0.05).The IC of meta-static lymph nodes were(2.968±0.547)g/L,(63.597±14.633)% for the NIC and(-2.532±0.753)for the slope of the virtual single energy spectrum curve.The IC of non-metastatic lymph nodes were(1.465±0.408)g/L,(35.240±14.357)%for the NIC and(-1.378±0.726)for the slope of the virtual single energy spectrum curve.They also had significantly statistical difference(P<0.05).Conclusion Dual-source CT dual-energy scan combined with three-dimensional reconstruction technique can help to determine the lesion range,improve the diagnostic rate of early gastric cancer,distinguish between metastatic and non-metastatic lymph nodes,and improve the accuracy of N staging.
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Objective The objective of this study was to determine the lesion range between gastric cancer lesions and normal gastric wall,improve the early diagnosis of gastric cancer rate,distinguish between me-tastatic lymph nodes and non-metastatic lymph nodes,and accurate N staging by dual-source CT double-en-ergy enhanced scan parameters.Methods The dual energy enhanced scan of patients with preoperative gastric cancer was performed by Siemens Somatom Definition Flash dual-source CT.The collected data were analyzed by Syngo.Via software and reconstructed three-dimensionally to obtain the absolute iodine of gastric cancer,nor-mal gastric wall,metastatic lymph node and non-metastatic lymph node value,standardized iodine value and vir-tual single energy spectrum curve of the slope to combine with postoperative pathological results.The use of statis-tical methods was to determine the difference between the post-and preoperation.Results The absolute iodine values(IC)were(3.329±0.812)g/L in the gastric cancer lesion and(64.006±17.450)% for the standard io-dine values(NIC).The slope of the virtual single energy spectrum curve was-2.916±1.3227,IC(1.563±0.708)g/L in the normal gastric wall.The NIC were(37.122±16.267)%and-1.621±1.4028 for the slope of the virtual single energy spectrum curve.They were significantly statistical difference(P<0.05).The IC of meta-static lymph nodes were(2.968±0.547)g/L,(63.597±14.633)% for the NIC and(-2.532±0.753)for the slope of the virtual single energy spectrum curve.The IC of non-metastatic lymph nodes were(1.465±0.408)g/L,(35.240±14.357)%for the NIC and(-1.378±0.726)for the slope of the virtual single energy spectrum curve.They also had significantly statistical difference(P<0.05).Conclusion Dual-source CT dual-energy scan combined with three-dimensional reconstruction technique can help to determine the lesion range,improve the diagnostic rate of early gastric cancer,distinguish between metastatic and non-metastatic lymph nodes,and improve the accuracy of N staging.
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Objective To measure the volume of pericardial adipose tissue (PAT) by a photons dual-source computed tomography (CT) (Somatom Definition Flash CT), and to analyze and evaluate the effects of pericardial adipose tissue volume on coronary artery imaging. Methods There were 123 patients with suspected coronary heart disease (CHD) who underwent CT coronary angiography (CTA) from February 2016 to August 2016 in our hospital were enrolled. According to the body mass index (BMI) of the patient, the tube current was set in the range of 100～400 mA and tube voltage was 100～120 kV. All the patients were divided into six groups from low to high based on the measured pericardial adipose tissue volumes. The coronary CTA imaging quality was evaluated by subjective scoring and objective comparison by calculating the signal-to-noise ratio and comparing the contrast-to-noise ratio. Statistical analysis was performed using Kmskal-Wallis rank sum test and Pearson correlation analysis. Results There was no significant difference in subjective scoring between different PAT groups (all P>0.05). There was no significant correlation between PAT content and signal-noise ratio and contrast noise ratio (P>0.05). Conclusions The pericardial adipose tissue volume has no significant effect on coronary artery CTA imaging.
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Objective To evaluate the image quality,diagnosis accuracy and dose reduction of split-bolus CT urography (CTU) with low voltage scan and sinogram affirmed iterative reconstruction (SAFIRE).Methods A total of 80 cases of consecutive patients with confirmed or suspected urinary system disease needed CTU examination were divided into two groups (control group and test group) by using random number table.In control group,convention scan (120 kV) with one time injection was used.But low voltage scan (80 kV) with SAFIRE algorithm and split-bolus injection (SBI) was used in experiment group.The radiation dose,image quality and diagnosis accuracy were compared.Results A total of 77 cases completed CTU examination successfully in the two groups,including 39 cases in control group and 38 cases in test group.The effective dose reduced from (26.68 ± 4.07) in control group to (3.93 ± 0.85) mSv in test group (t =-33.78,P ＜ 0.05).Subjective image quality score was (4.49 ± 0.79) in control group and (4.39 ± 1.53) in test group,with no significantly statistical difference (Z =2.71,P ＞ 0.05).Signal-to-noise ratio (SNR) of objective image quality in test group was higher than that in control group (127.3±15.9 vs.109.6 ± 13.2,t =4.49,P＜0.05).But there was no significantly statistical difference in contrast-to-noise ratio (CNR) between control group(100.8 ± 12.9)and test group (109.0 ± 14.4,P ＞ 0.05).For diagnosis accuracy,no statistical difference were found between two groups(84.62％ and 81.58％,P ＞ 0.05).Conclusions The combination of low voltage scan with SAFIRE algorithm and split-bolus injection CTU could reduce the radiation dose significantly,but the objective image quality,CNR (except SNR) of subjective image quality and diagnosis accuracy were all unaffected obviously.
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Objective:To explore the clinical value of dual-source CT direct method lower extremity deep vein CT angiography (DSCTV) and Doppler ultrasound (DUS) in the diagnosis of thrombosis in inferior vena cava and bilateral lower extremities deep venous.Methods: 40 suspected patients with lower extremities deep vein thrombosis (DVT) were enrolled to accept DSCTV, and the every original image data of this detection was analyzed by using multi- mode image reconstruction analysis. One week before and after DSCTV, all of patients need carried out DUS detections for inferior vena cava and bilateral lower extremities deep venous. 22 cases of these patients were detected by lower extremity deep vein X-ray digital subtraction angiography (DSA).Results: There was better consistency for diagnosis results between DUS and DSCTV, and their Kappa value was 0.784. The sensitivity, specificity and accuracy of DUS for lower extremity DVT, respectively, were 93.4%, 86.7% and 91.6%, and each result of DUS was lower than that of DSCTV (sensitivity with 97.2%, specificity with 91.1% and accuracy with 95.6%). By drawing ROC curve, the AUC value of DUS was 0.897, and that of DSCTV was 0.936, while the difference between them was no significant (Z=1.143,P>0.05).Conclusion: DSCTV possesses unique scanning and post-processing technique, which has a good reference value in the diagnosis for DVT
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Objective To explore the value of dual-source dual-energy CT (DSDE-CT) in differentiating extravasation of iodine contrast agents from secondary hemorrhage after revascularization in acute ischemic stroke. Methods 46 acute ischemic stroke patients following intra-arterial thrombolysis were examined with DSDE-CT within 2 hours after the procedure. Simultaneous imaging at 80 kV/392 mA and 140 kV/196 mA was employed, and then mixed images, virtual unenhanced non-contrast images and iodine overlay maps were calculated. Mixed images alone, as conventional CT, and DUDE-CT interpretations were assessed separately by two radiologists and compared with follow-up CT. Results 6 of 34 patients were negative cases proven by CT without high density, and another 28 cases were proven positive cases with 3 cases of cerebral hemorrhage, 21 cases of contrast agent extravasation, and the remaining 4 cases of combined cerebral hemorrhage and contrast agent extravasation. The sensibility, specificity, positive predictive value, negative predictive value and accuracy of mixed imaging alone in diagnosing hemorrhage was 66.67%, 100%, 1005, 96.15% and 96.43%, while the sensibility, specificity, positive predictive value, negative predictive value and accuracy of hemorrhage with DUDE-CT was 100%, 96%, 75%, 100% and 96.43% . The diagnostic accuracy of superimposed fusion images for intracranial hemorrhage, extravasation of contrast agent and hemorrhage with extravasation of contrast agent was relatively high, and the difference was statistically significant (P < 0.05). The diagnostic accuracy of superimposed fusion images consistent with clinical follow-up was significantly higher (Kappa=0.815),as compared with that of mixed imaging alone (Kappa=0.0.564). Conclusion DUDE-CT has great value in differentiating hemorrhage from iodinated contrast after intra-arterial thrombolysis in acute ischemic stroke.
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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.
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Objective To explore the potential relationship between left coronary bifurcation angle and plaques forming in left anterior descending artery by dual-source CT angiography.Methods One hundred patients who underwent dual-source CT angiography in our hospital from January to May during 2016 and had plaques in left anterior descending artery were retrospectively studied,while 100 patients with normal image were as negative controls.There were 57 male and 43 female at the mean age of (57.54 ±-8.38) years in negative controls,and 64 male and 36 female at the mean age of (62.08 ± 13.94) years in patients with left anterior descending artery plaques.The left coronary bifurcation angle was measured by multi-planar reconstruction (MPR) and maximum density projection (MIP) techniques.Results The left coronary bifurcation angle in negative control group were range from 41.25°to 112.14°,at the mean age of 69.45 ° ± 18.71 °,while range from 54.14 ° to 128.12 o,at the mean age of 85.65 °-± 15.96 ° in plaque group.The bifurcation angle in plaque group was larger than those in negative control group(P ＜ 0.05).Conclusion Dual-source CTA could objectively evaluate left coronary bifurcation angle and plaque character.The left coronary bifurcation angle had an important influence on the formation of left anterior descending artery plaque.