ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.
Subject(s)
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.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
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
ABSTRACT
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.
ABSTRACT
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.
ABSTRACT
Objective To evaluate the clinical value of myocardial perfusion imaging with dual-source dual-energy CT and a contrast agent at a low concen.tration in the diagnosis of myocardial infarction in the elderly Methods One-stop cardiac imaging with dual-source CT was conducted in 138 elderly patients diagnosed with myocardial infarction between October 2015 and May 2016.The patients were randomly divided into two groups,Group A and Group B,each with 69 patients.Myocardial perfusion was performed for coronary imaging,using 70 ml Visipaque(270 g/L)and 50 ml saline for Group A and 70 ml iopromide(370 g/L)and 50 ml saline for Group B.Myocardial transmural perfusion gradients(TPG)were calculated,and the total iodine dose and the rate of iodine infusion were compared between the two groups.Results The procedure was successfully carried out in all 138 patients.There was no statistically significant difference in TPG between the two groups in the right coronary artery,the anterior descending artery and the circumflex artery(P＞0.05).The total iodine dose for Group A was 18.5 g,27％ less than that for Group B(25.9 g).The rate of iodine infusion for Group A was 3.5 g/s,also 27％ less than that for GroupB(18.5 g/s).Conclusions Myocardial perfusion imaging with dual-source dual-energy CT and contrast agents at low concentrations is a promising approach,which is capable of achieving quality imaging for the assessment of myocardial infarction with reduced use of iodine and represents a clinically valuable option.
ABSTRACT
Objective To study the impact on the radiation dose,organ doses of eye lens and thyroid and image quality with different scanning modes in head and neck CT scan.Methods The simulation phantom of head and neck was scanned by using fixed scanning condition (120 kV and 200 mAs),as well as the combinations of automatic tube current modulation (CARE Dose 4D),automatic tube voltage modulation technique (CARE kV) and partial angle scanning mode (X-CARE) respectively.Six kinds of scanning modes were adopted,including 120 kV +200 mAs,120 kV + 200 mAs + X-CARE,CARE Dose 4D + 120 kV,CARE Dose 4D + 120 kV + X-CARE,CARE Dose 4D + CARE kV,CARE Dose 4D + CARE kV + X-CARE.Two thermolumineseece dosimeters (TLDs) were exposed at the skin surface positions of eye lens and thyroid,and the values measured with two TLDs were averaged.The CT dose index volume (CTDIvol) and dose length product (DLP) for every scan were recorded,and the contrast to noise ratio (CNR) in eye lens section and thyroid section were measured.Results The crgan doses of lens and thyroid were 19.8 and 26 mGy at 120 kV and 200 mAs,as well as 13.3 and 22.2 mGv at X-CARE mode.Compared with the manual selection of 120 kV,the combination of CARE kV and CARE Dose 4D made the values of CTDIvol drop from 13.1 to 10.1 mGy,the doses of eye lens and thyroid from 16.6 and 20.8 mGy to 23.7 and 19.9 mGy respectively,while the image quality reducedsignificantly.Compared with CARE Dose 4D + 120 kV,the organ doses of eye lens and thyroid were reduced from 20.8 and 23.7 mGy to 9.6 and 15.1 mGy for with additional X-CARE,while CTDIvol dropped from 13.1 to 9.3 mGy.When the combination of CARE Dose 4D + CARE kV + X-CARE was used,CTDIvol and organ doses were reduced to a minimum,when the CNRs of head and neck were also minimized.Conclusions The scanning mode CARE Dose 4D + 120 kV + X-CARE for head and CARE Dose 4D + CARE kV for neck can effectively reduce the radiation dose while keeping good image quality.When requirements for image quality are not high,CARE Dose 4D + CARE kV + X-CARE mode can be selected to reduce the radiation dose significantly.
ABSTRACT
Objective To determine the diagnostic accuracy of dual- source computed tomography coronary angiography (DSCT-CA) for detecting various degrees of coronary artery stenosis. Methods A total of 278 patients with coronary atherosclerotic heart disease (CHD) were selected for DSCT-CA examination. The coronary angiography (CAG) examination was carried out within 30 days in these patients. The result of CAG was used as the gold standard. The coronary artery stenosis of 50% and 75% was used as the sector. Based on the data of patients, DSCT-CA was calculated for quantitative assessment of the sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of coronary stenosis for the coronary blood vessels and coronary artery segments. Kappa consistence test was used to analyze the results of two methods. Results The 50%and 75%of coronary artery stenosis was used for the sector, based on the patients, the sensitivities of DSCT-CA were 99.6% and 99.1%, specificities were 84.2%, 89.6%, diagnostic accuracies were 98.6%and 97.5%, and the Kappa values were 0.88 and 0.91. Based on coronary vessels, the sensitivities were 92.0%and 96.9%, specificities were 89.9%and 94.8%, diagnostic accuracies were 91.0%and 95.8%, and the Kappa values were 0.88 and 0.92. Based on coronary artery segments, the sensitivities were 97.3%, 96.5%, specificities were 93.3%, 98.1%, diagnostic accuracies were 94.2%and 97.9%, and the Kappa values were 0.84 and 0.91. Conclusion Based on patient’s coronary artery analysis, DSCT-CA can accurately assess the different degrees of coronary stenosis, but based on the analysis of the coronary artery segment, the false-positive results may occur in the diagnosis of DACT-CA, which suggests that DSCT-CA can partly replace the CAG, still cannot completely replace the CAG.
ABSTRACT
Objective To analyze spectral curves and iodine levels in normal adult thyroid by using dual-source CT scanning technique and provide the basis for the differential diagnosis of thyroid space-occupying lesions.Methods A total of 70 subjects were selected for this study,including 38 females and 32 males.They were excluded from thyroid disease by ultrasound examination and had all taken the dual-source CT scan.The image data were transported to the CT workstation,the analysis of iodine levels and spectral curves were completed in theLiver VNCandMonoenergetic modes respectively.The gender differences in ratio iodine content were compared.Results The iodine ratio of thyroid was (1.35±0.19) mg/mlin plain scan,(1.35±0.23) and (1.35±0.21) mg/ml in left lobe and right lobe respectively.There was no statistically significant difference between left and right lobe (P ＞ 0.05),as well as between females and males (P ＞ 0.05).The slopes of the energy spectrum curve in the left and right lobe of the thyroid were 9.98 ± 2.43 and 9.74 ± 1.63,respectively,and 9.88 ± 1.74 and 9.74 ±0.09 for the male and female,respectively.There was no significant difference of slopes of the energy spectrum curve between the left and right lobe,as well as the male and female.The average dose length product of all patients was (208.29 ±21.80) mGy·cm,and the average effective dose was (1.23 ± 0.13) mSv.Conclusions Dual-source dual-energy CT scanning technique have definitive,diagnostic characteristic in the measurement of spectral curves and calculation of the ratio of iodine in normal adult thyroid tissue,and therefore has guidance value in the diagnosis of thyroid space-occupying lesions.
ABSTRACT
[Abstract ] Objective To compare the accuracy between regular computed tomography colonography (CTC)and dual-energy CTC in lesion detection.Methods Twenty-eight patients with clinical suspicious space occupying lesions of the colon were selected.All patients were underwent dual-energy mode contrast-enhanced CT scan and the data were reconstructed with colonography and dual-energy iodine maps methods.The diameter,enhanced computed tomography (CT)value and iodine value were measured.The results of colonoscopy and pathology were taken as gold standard.The sensitivity, specificity,accuracy,positive predictive value and negative predictive value of regular CTC and dual-energy CTC were compared.Variance analysis was performed for measurement data comparison among groups and chi-square test was used for count data analysis.Results Among 28 patients,colorectal lesions were detected in 24 cases by regular CTC,of which four cases were false-positive and one case was false-negative confirmed by colonoscopy and pathology.Colorectal lesions were detected in 20 cases by dual-energy CTC,of which no false-positive and one case was false negative confirmed by colonoscopy and pathology.The contrast enhanced CT value of polyps,adenoma,adenocarcinoma and stool was (38.54± 6.82),(49.16±7.31 ),(52.61 ±5 .93 )and (34.00±1 .41 )Hu,respectively.The enhanced value of adenoma and adenocarcinoma was significantly higher than that of polyps and stool,the differences were statistically significant among groups (F = 10.760,P = 0.001 ).There was no significant difference between polyps and stool (t=1 .44,P =0.188).The sensitivity of regular CTC and dual-energy CTC in lesion detection was 95 .6% (95 %cofidence interval(CI ):77.9%-99.2%)and 95 .6% (95 %CI :77.9%-99.2%),respectively.The specificity was 42.8% (95 %CI :15 .4%-93.5 %)and 100.0% (95 %CI :47.9%-100.0%).Conclusion Compared with traditional CTC,dual-energy CTC would distinguish lesions from stool,help differentiate between benign and malignant tumors and further increase the accuracy of CTC diagnosis.
ABSTRACT
Objective: To investigate the therapeutic value of dual source CT coronary CTA (DSCTA) in coronary atherosclerosis. Methods: Ninety five cases with clinical highly suspected coronary artery disease in DSCTA were selected from January 2013 to December 2014, coronary angiography (CAG) as thegold standard, analysis of DSCTA assessment of coronary artery stenosis and coronary artery display accuracy and consistency of CAG findings. Results: ①CAG inspection coronary artery stenosis with mild, moderate stenosis, severe stenosis were 149, 81, 55, DSCTA accurate assessment of were respectively 140, 79, 54, accuracy rate of 95.79 %, consistency test was statistically significant (Kappa=0.679, P5 were 8 cases, 68 cases, 19 cases, DSCTA were accurately detected in 8 cases, 65 cases, 15 cases, accuracy rate of 92.63%, consistency test was statistically significant(Kappa=0.608, P<0.05). Conclusion:DSCTA in assessing the degree of stenosis of coronary atherosclerosis and coronary branch vessels show areas with good results, worthy of recognition in clinical.