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Objective@#To evaluate the image quality of novel dark-blood computed tomography angiography (CTA) imaging combined with deep learning reconstruction (DLR) compared to delayed-phase CTA images with hybrid iterative reconstruction (HIR), to visualize the cervical artery wall in patients with Takayasu arteritis (TAK). @*Materials and Methods@#This prospective study continuously recruited 53 patients with TAK (mean age: 33.8 ± 10.2 years; 49 females) between January and July 2022 who underwent head-neck CTA scans. The arterial- and delayed-phase images were reconstructed using HIR and DLR. Subtracted images of the arterial-phase from the delayed-phase were then added to the original delayed-phase using a denoising filter to generate the final-dark-blood images. Qualitative image quality scores and quantitative parameters were obtained and compared among the three groups of images: Delayed-HIR, Dark-blood-HIR, and Dark-blood-DLR. @*Results@#Compared to Delayed-HIR, Dark-blood-HIR images demonstrated higher qualitative scores in terms of vascular wall visualization and diagnostic confidence index (all P < 0.001). These qualitative scores further improved after applying DLR (Dark-blood-DLR compared to Dark-blood-HIR, all P < 0.001). Dark-blood DLR also showed higher scores for overall image noise than Dark-blood-HIR (P < 0.001). In the quantitative analysis, the contrast-to-noise ratio (CNR) values between the vessel wall and lumen for the bilateral common carotid arteries and brachiocephalic trunk were significantly higher on Darkblood-HIR images than on Delayed-HIR images (all P < 0.05). The CNR values were significantly higher for Dark-blood-DLR than for Dark-blood-HIR in all cervical arteries (all P < 0.001). @*Conclusion@#Compared with Delayed-HIR CTA, the dark-blood method combined with DLR improved CTA image quality and enhanced visualization of the cervical artery wall in patients with TAK.
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Objective:To construct a machine-learning model for predicting the progression of pancreatic cystic lesions (PCLs) based on clinical and CT features, and to evaluate its predictive performance in internal/external testing cohorts.Methods:Baseline clinical and radiological data of 200 PCLs in 177 patients undergoing abdominal thin slice enhanced CT examination at Peking Union Medical College Hospital from July 2014 to December 2022 were retrospectively collected. PCLs were divided into progressive and non-progressive groups according to whether the signs indicated for surgery by the guidelines of the European study group on PCLs were present during three-year follow-up. 200 PCLs were randomly divided into training (150 PCLs) and internal testing cohorts (50 PCLs) at the ratio of 1∶3. 15 PCLs in 14 patients at Jinling Affiliated Hospital of Medical School of Nanjing University from October 2011 to May 2020 were enrolled as external testing cohort. The clinical and CT radiological features were recorded. Multiple feature selection methods and machine-learning models were implemented and combined to identify the optimal machine-learning model based on the 10-fold cross-validation method. Receiver operating characteristics (ROC) curve was drawn and area under curve (AUC) was calculated. The model with the highest AUC was determined as the optimal model. The optimal model's predictive performance was evaluated on testing cohort by calculating AUC, sensitivity, specificity and accuracy. Permutation importance was used to assess the importance of optimal model features. Calibration curves of the optimal model were established to evaluate the model's clinical applicability by Hosmer-Lemeshow test.Results:In training and internal testing cohorts, the progressive and non-progressive groups were significantly different on history of pancreatitis, lesions size, main pancreatic duct diameter and dilation, thick cyst wall, presence of septation and thick septation (all P value <0.05) In internal testing cohort, the two groups were significantly different on gender, lesion calcification and pancreatic atrophy (all P value <0.05). In external testing cohort, the two groups were significantly different on lesions size and pancreatic duct dilation (both P<0.05). The support vector machine (SVM) model based on five features selected by F test (lesion size, thick cyst wall, history of pancreatitis, main pancreatic duct diameter and dilation) achieved the highest AUC of 0.899 during cross-validation. SVM model for predicting the progression of PCLs demonstrated an AUC of 0.909, sensitivity of 82.4%, specificity of 72.7%, and accuracy of 76.0% in the internal testing cohort, and 0.944, 100%, 77.8%, and 86.7% in the external testing cohort. Calibration curved showed that the predicted probability by the model was comparable to the real progression of PCLs. Hosmer-Lemeshow goodness-of-fit test affirmed the model's consistency with actual PCLs progression in testing cohorts. Conclusions:The SVM model based on clinical and CT features can help doctors predict the PCLs progression within three-year follow-up, thus achieving efficient patient management and rational allocation of medical resource.
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Objective To investigate the effect of different radiation doses on the accuracy of iodine quantification and CT value of virtual monochromatic image with a muti-spectral CT iodine phantom using second-generation dual-layer detector spectral CT(DLCT).Methods The second-generation DLCT scan abdominal phantom was used,which consisted of six different concentrations of iodine rods at 4,8 and 12 g/L.The scan parameters were set at 100,120 and 140 kVp tube voltages,and six radiation exposure sequences were scanned at each tube voltage:5,10,15,20,25 and 30 mGy.Measure the iodine concentration value and the CT value at the single level of 50,70 and 100 keV,and calculate the absolute error value of iodine concentration and CT value under different radiation exposure.SPSS 22.0 software single factor analysis of variance was used to compare the difference between the io-dine concentration and the absolute error of CT value under different Radiation exposure,and LSD method was used to compare the two groups.Results The absolute error of CT value of 4 g/L iodine rod with 10~30 mGy scanning at 100 keV energy level was significantly higher than that of 12 g/L and 8 g/L(P<0.05),and the absolute error of iodine concentration measurement of other iodine rods with different concentrations at different Radiation exposure had no statistical difference.Conclusions The second-generation double-layer detector spectral CT has high meas-urement stability for iodine concentration quantification and CT value accuracy under conditions of radiation dose greater than 5 mGy.
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Objective:To evaluate the effectiveness of deep learning reconstruction (DLR) compared with hybrid iterative reconstruction (Hybrid IR) in improving the image quality in chest low-dose CT (LDCT).Methods:Seventy-seven patients who underwent LDCT scan for physical examination or regular follow-up in Peking Union Medical College Hospital from October 2020 to March 2021 were retrospectively included. The LDCT images were reconstructed with Hybrid IR at standard level (Hybrid IR Stand) and DLR at standard and strong level (DLR Stand and DLR Strong). Regions of interest were placed on pulmonary lobe, aorta, subscapularis muscle and axillary fat to measure the CT value and image noise. The signal to noise ratio (SNR) and contrast to noise ratio (CNR) were calculated. Subjective image quality was evaluated using Likert 5-score method by two experienced radiologists. The number and features of ground-glass nodule (GGN) were also assessed. If the scores of the two radiologists were inconsistent, the score was determined by the third radiologist. The objective and subjective image evaluation were compared using the Kruskal-Wallis test, and the Bonferroni test was used for multiple comparisons within the group.Results:Among Hybrid IR Stand, DLR Stand and DLR Strong images, the CT value of pulmonary lobe, aorta, subscapularis muscle and axillary fat had no significant differences (all P>0.05), but the image noise and SNR of pulmonary lobe, aorta, subscapularis muscle and axillary fat had significant differences(all P<0.05), and the CNR of images had significant difference( P<0.05), too. The CNR of Hybrid IR Stand images, DLR stand images and DLR strong images were 0.71 (0.49, 0.88), 1.06 (0.78, 1.32) and 1.14 (0.84, 1.48), respectively. Compared with Hybrid IR images, DLR images had lower objective and subjective image noise,higher SNR and CNR (all P<0.05). The scores of DLR images were superior to Hybrid IR images in identifying lung fissures, pulmonary vessels, trachea and bronchi, lymph nodes, pleura, pericardium and GGN (all P<0.05). Conclusions:DLR significantly reduced the image noise, and DLR images were superior to Hybrid IR images in identifying GGN in chest LDCT while maintaining superior image quality at relatively low radiation dose levels. Thus DLR images can improve the safety of lung cancer screening and pulmonary nodule follow-up by CT.
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Objective:To investigate the feasibility of coronary CT angiography(CCTA)-feature tracking(FT) for assessing global and regional myocardial strain in patients with heart failure(HF).Methods:From July 2019 to December 2020, twenty-five patients diagnosed with HF from Peking Union Medical College Hospital were prospectively enrolled into the study. All patients underwent retrospective electrocardiogram-gated CCTA and cardiac MR (CMR) imaging within 7 days. CCTA-FT and CMR-FT were undertaken using cvi 42 dedicated commercial software to measure global and regional strain parameters, including global peak radial strain (GPRS), global peak circumferential strain (GPCS) and global peak longitudinal strain (GPLS), as well as peak radial strain (PRS), peak circumferential strain (PCS) and peak longitudinal strain (PLS) of left ventricular basal segment, middle segment and apical segment. Conventional left ventricular functional parameters were also calculated, including left ventricular ejection fraction (LVEF), left ventricular stroke volume (LVSV) and left ventricular mass index (LVMI). Paired t test or Wilcoxon signed-rank test was used to compare the differences of measurements between CCTA group and CMR group. Pearson or Spearman correlation analysis was used to analyze the correlation between the two groups. Inter-and intra-observer consistence in CCTA group was evaluated by intraclass correlation coefficient (ICC) analysis. Results:The effective radiation dose of CCTA examination was 6.00 (4.86,7.63) mSv. Inter-and intra-observer consistence in CCTA group was excellent, and the ICC value was 0.85-0.98. In the overall strain parameters, GPCS in CCTA group[-8.10%(-10.32%, -5.20%)] was significantly lower than that of CMR group[-8.49%(-13.79%, -5.95%)] ( Z=-2.15, P=0.031). There was no significant difference in GPRS and GPRS between the two measurement methods ( P>0.05). Strong correlations were observed between GPRS, GPCS and GPLS ( r=0.65, 0.63, 0.71,all P<0.001). For local strain parameters, PCS in the middle segment and apical segment of CCTA group were lower than those of CMR group ( Z=-2.17, -2.62, all P<0.05). There were no significant differences in PCS of basal segment, PRS and PLS of all segments between groups (all P>0.05). The PCS and PLS of basal segment, PRS of middle segment and PRS of apical segment were moderately correlated ( r=0.46, 0.52, 0.58, 0.53, P<0.05); The other local strain parameters were strongly correlated, the range of r value was from 0.64 to 0.70 (all P<0.001). For left ventricular functional parameters, LVEF, LVSV and LVMI showed no significant differences between groups ( P>0.05), and the correlation was extremely strong ( r=0.90, 0.89, 0.96, all P<0.001). Conclusions:The repeatability of CCTA-FT technique in measuring myocardial strain was good, and the correlation of parameters measured by CCTA-FT technique and CMR-FT technique was excellent. Therefore, CCTA-FT technique can be used as a new noninvasive and simple method to evaluate myocardial motor function.
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Objective:To explore application value of improving quality of the low dose pancreatic CT images by using deep learning reconstruction (DLR).Methods:From August to December 2020, 68 patients who underwent contrast-enhanced pancreatic CT were prospectively collected in Peking Union Medical College Hospital. All patients were randomly divided into routine dose group (34 patients, with tube voltage of 120 kV) and low dose group (34 patients, with tube voltage of 100 kV). All patients underwent non-contrast, arterial phase, parenchymal phase and delay phase scans. The four-phase images of low dose group were reconstructed by using filtered back projection (FBP), hybrid iterative reconstruction (AIDR) and DLR which were marked with LD-FBP, LD-AIDR and LD-DLR, respectively. The four-phase images of routine dose group were reconstructed by using AIDR algorithm which were marked with RD-AIDR. The CT value, image noise (SD), signal to noise ratio (SNR) and contrast to noise ratio (CNR) of pancreas were measured. The ANOVA test was performed in comparison with objective parameters of different reconstruction algorithms, and LSD test was performed in pairwise comparison. The subjective image scores were obtained and were compared using Kruskal-Wallis test.Results:CT value, SD, SNR and CNR of non-contrast, arterial phase, parenchymal phase and delay phase had significant difference among different reconstruction images of routine dose group and low dose group (all P<0.05). The CT value of LD-FBP, LD-AIDR, and LD-DLR images were significantly higher than those of RD-AIDR images in parenchymal phase and delay phase (all P<0.05). There were statistically significant differences in each pairwise comparison of SD and SNR of four phase images (all P<0.05). There were statistically significant differences of CNR among LD-FBP, LD-DLR and RD-AIDR in four phase images (all P<0.05). The CNR of RD-AIDR was better than that of LD-FBP, and CNR of LD-DLR was better than that of RD-AIDR. DLR algorithm improved the SD, SNR and CNR of four phases of pancreatic images. The improvement of SNR was more significant after contrast enhancement, and the improvement of CNR was more significant in the non-contrast and delay phases. Subjective image scores of different reconstruction images were statistically different in four phase images (all P<0.001). Overall image scores of LD-DLR and RD-AIDR had no significant differences in four phase ( Z value of four phases were 1.00, 2.24, 0.45 and 1.34, respectively; P value of four phases were 0.317, 0.025, 0.655 and 0.180, respectively). Conclusion:The DLR technology can decrease radiation dose of pancreatic CT, improve image quality and satisfy diagnostic requirement. The DLR technology can also reduce image noise, improve the SNR and CNR in low dose contrast-enhanced pancreatic CT.
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Objective:To explore the effect of deep learning reconstruction (DLR) on radiation dosage reduction and image quality of CTPA compared with hybrid iterative reconstruction (HIR).Methods:A total of 100 patients with suspected pulmonary embolism (APE) or indications for CTPA due to other pulmonary artery diseases in Peking Union Medical College Hospital from December 2020 to April 2021 were prospectively enrolled and divided into HIR group and DLR group according to block randomization, with 50 cases in each group. The patient′s gender, age and body mass index (BMI) were recorded. HIR group and DLR group underwent standard deviation (SD)=8.8 and SD=15 CTPA protocols in combination with HIR and DLR algorithm respectively. Other scanning parameters and contrast medium injection plan were the same. The effective dose (ED) and size-specific dose estimate (SSDE) were calculated. Regions of interest (ROIs) were drawn in the lumen of Grade 1-3 pulmonary arteries and bilateral paravertebral muscles. The corresponding CT and SD values were recorded to acquire signal to noise ratio (SNR) and contrast noise ratio (CNR). Based on a double-blind method, two radiologists evaluated the subjective noise, visualization of pulmonary arteries, and diagnostic confidence of the two groups by 5-point Likert scales. The inconsistent results were judged comprehensively by the third radiologist. Independent samples t-test was used to compare the demographic data, radiation dosage and quantitative image quality of the two groups. Mann-Whitney U test was used to compare the subjective noise, visualization of pulmonary arteries and diagnostic confidence between the two groups. Linear weighted Kappa coefficient was calculated to analyze the consistency of the qualitative scores between the two radiologists. Results:There were no significant differences in gender, age and BMI between the two groups ( P>0.05). The CT values of Grade1-3 pulmonary arteries and paravertebral muscle had no significant differences ( P>0.05). Compared with HIR group, the ED and SSDE in DLR group decreased by about 35% to 1.3 mSv and 4.20 mGy respectively, while the SNR (30±5) and CNR (26±5) of CTPA images were higher in DLR group than those in HIR group (23±5 and 20±5, with t=-6.60 and -5.90, respectively, both P<0.001). The subjective noise score was higher in DLR group than that in HIR group ( Z=-7.34, P<0.001). In addition, two radiologists showed excellent interobserver agreement in DLR group (Kappa=0.847, 95%CI 0.553-1.000). No significant differences were found in visualization of pulmonary arteries and diagnostic confidence between the two groups ( P>0.05). Conclusion:DLR further reduced the radiation dosage and improved the image quality of CTPA, with no detriment to diagnostic confidence. Thus DLR is worthy of clinical promotion.
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Objective:To investigate the feasibility of chest ultra-low dose CT (ULDCT) using deep learning reconstruction (DLR) for lung cancer screening, and to compare its image quality and nodule detection rate with ULDCT iterative reconstruction (Hybrid IR) and conventional dose CT (RDCT) Hybrid IR.Methods:The patients who underwent chest CT examination for pulmonary nodules in Peking Union Medical College Hospital from October 2020 to March 2021 were prospectively included and underwent chest RDCT (120 kVp, automatic tube current), followed by ULDCT (100 kVp, 20 mA). The RDCT images were reconstructed with Hybrid IR (adaptive iterative dose reduction 3D,AIDR 3D), and ULDCT was reconstructed with AIDR3D and DLR. Radiation dose parameters and nodule numbers were recorded. Image quality was assessed using objective noise, signal-to-noise ratio (SNR) of the main trachea and left upper lobe, subjective image scores of the lung and nodules. Subjective scores were scored by 2 experienced radiologists on a Likert 5-point scale. The difference of radiation dose was compared with paired t-test between ULDCT and RDCT.The differences of quantitative indexes, objective image noise and subjective scores of the three reconstruction methods were compared with one-way analysis of variance or Friedman test. Results:Forty-five patients were enrolled, including 17 males and 28 females, aged from 32 to 74 (55±11) years. The radiation dose of ULDCT was (0.17±0.01) mSv, which was significantly lower than that of RDCT [(1.35±0.41) mSv, t=15.46, P<0.001]. There were significant differences in the image noise and SNR in the trachea and lung parenchyma and in the CT value of the trachea among ULDCT-AICE, ULDCT-AIDR 3D and RDCT-AIDR 3D images ( P<0.05). Image noise in the trachea and lung parenchyma and CT value in the trachea of ULDCT-AICE were significantly lower than those of ULDCT-AIDR 3D ( P<0.05) and comparable to RDCT-AIDR 3D ( P>0.05). There were significant differences in subjective image scores of the lung and nodules among ULDCT-AICE, ULDCT-AIDR 3D and RDCT-AIDR 3D images (χ2=50.57,117.20, P<0.001). Subjective image scores of the lung and nodules for ULDCT-AICE were significantly higher than those of ULDCT-AIDR 3D ( P<0.05), and non-inferior to RDCT-ADIR 3D ( P>0.05). All 72 clinically significant nodules detected on RDCT-ADIR 3D were also noted on ULDCT-AICE and ULDCT-AIDR 3D images. Conclusions:Chest ULDCT using DLR can significantly reduce the radiation dose, and compared with Hybrid IR, it can effectively reduce the image noise and improve SNR, and display the pulmonary nodules well. The image quality and nodule detection are not inferior to RDCT Hybrid IR routinely used in clinical practice.
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Objective:To investigate the correlation between amide proton transfer-weighted (APTw) values and Ki-67 labeling index of cervical squamous cell carcinoma.Methods:From October 2017 to December 2018, 24 patients with cervical squamous cell carcinoma [International Federation of Gynecology and Obstetrics (FIGO) stage Ⅰ-Ⅲ] were prospectively enrolled in Peking Union Medical College Hospital and underwent pelvic morphological MRI on a 3.0 T MR scanner, including three-dimensional turbo-spin-echo APTw imaging and DWI. The maximum diameters of the lesions, APTw values and ADC values on the slice with the maximum diameter of the lesion were independently measured by two radiologists. The ICC was computed to evaluate the inter-observer consistency. Ki-67 immunohistochemical expression status was assessed by one pathologist. The Pearson correlation analysis was performed between the APTw values, maximum diameters, ADC values and Ki-67 labeling index.Results:The APTw values of cervical squamous cell carcinoma were (2.9±0.5)%. Inter-observer ICC was 0.972 (95%CI 0.937-0.988). The APTw values were positively moderately correlated with Ki-67 labeling index [(61.9±18.7)%, r=0.532, P=0.008]. The maximum diameters of the lesions were (28.7±10.6) mm. The mean ADC values were (0.998±0.217)×10 -3 mm 2/s. No correlations were found between maximum diameters, ADC values and Ki-67 labeling index ( r=0.038, P=0.859; r=0.238, P=0.263). Conclusion:APTw values can partially reveal the proliferation status of cervical squamous cell carcinoma.
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Objective:To explore the feasibility in evaluating segmental extracellular volume (ECV) using dual-layer spectral detector CT in patients with heart failure with various percentages of delayed hyper-enhanced volume, using MRI as a reference.Methods:Twenty-seven patients with heart failure in Peking Union Medical College Hospital were prospectively enrolled in this study from July 2019 to January 2021. All the patients underwent both CT late iodine enhancement and MR late gadolinium enhancement imaging within a week. According to percentages of hyper-enhanced volume on cardiac MR image, myocardial segments were classified into 3 groups: 0-4% (group A), 5%-49% (group B) and 50%-100% (group C). ECV images were independently observed by 2 experienced radiologists. The correlation and agreement between CT-ECV and MRI-ECV for the whole myocardial assessment and for the segmental assessment were evaluated using Spearman correlation and Bland-Altman analysis. Inter-observer agreement was assessed using the ICC.Results:Of the 27 patients, 432 segments were analyzed, with 199 segments in group A, 151 segments in group B and 82 segments in group C. In the whole myocardial analysis, the CT-ECV and MRI-ECV were 32.25% (28.04%, 34.28%) and 32.27% (28.35%, 34.77%), respectively. A good correlation was found between CT-ECV and MRI-ECV ( r=0.969, P<0.001). Bland-Altman analysis between CT-ECV and MRI-ECV showed a small bias (0.4%), with 95% limits of agreement of -6.9% to 7.8%. as for the segmental myocardial assessment, the CT-ECV was 28.23% (26.18%, 29.92%) for group A, 33.29% (30.16%, 35.96%) for group B and 40.22% (34.06%, 46.70%) for group C. There was statistically significant difference in ECV among three groups (all P<0.001). Good correlations between CT-ECV and MRI-ECV were found in group A ( r=0.614, P<0.001), group B ( r=0.852, P<0.001) and group C ( r=0.953, P<0.001). Bland-Altman analysis between CT-ECV and MRI-ECV showed a small bias 2.0% (95% limits of agreement:-17.6%-21.6%) in group A, a small bias -0.4% (95% limits of agreement: -13.8%-12.9%) in group B and a small bias -1.8% (95% limits of agreement: -17.4%-13.9%) in group C. The ICC values between 2 observers were 0.877 and 0.945 on CT-ECV and MRI-ECV, respectively. Conclusions:The larger percentage of hyper-enhanced volume on cardiac MR image, the stronger correlation are between the CT-ECV and MRI-ECV. CT-ECV may be taken as an alternative tool for quantitative evaluation of myocardial tissue in patients with heart failure.
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Objective:To explore the application value of 3.0 T MultiVane XD (MVXD) technique in female patients with uterine adenomyosis and fibroids.Methods:Patients diagnosed with uterine fibroids with ultrasound and suspected of adenomyosis were involved prospectively from March to May 2018, 3.0 T pelvic MRI examinations were performed during peri-ovulatory period. Axialconventional turbo spin echo (TSE) T 2WI, axial MVXD T 2WI, sagittal conventional TSE T 2WI and MVXD sagittal T 2WI were acquired. Two observers rated those 4 series in the aspects of sharpness of uterine border, motion artifacts, identification capability of lesions, confidence of diagnosis and overall image quality. Cohen Kappa analysis was used to evaluate the consistency of scores between 2 observers. Scores of TSE T 2WI and MVXD T 2WI qualities were compared using Wilcoxon matched-pairs signed-ranks test. Results:Twenty patients were enrolled. Axial conventional TSE T 2WI, axial MVXD T 2WI were aquired on all of them. Sagittal conventional TSE T 2WI, sagittal MVXD T 2WI were aquired on 19 among them. Nine patients had only obvious adenomyosis, 6 had only uterinefibroids, and 5 had adenomyosis and uterine fibroids. Compared to conventional TSE technique, scores of two observers in the sharpness of uterine border, motion artifacts, and overall image quality is higher by MVXD with significant difference ( P<0.05). The Kappa values for image quality scores of two observers ranged from 0.615 to 0.971, the agreement was good or very good. Conclusion:Applying MVXD T 2WI technique to patients with uterine fibroids and adenomyosiscould improve image quality, without sacrificing the ability to recognize and diagnose lesions, compared to conventional TSE T 2WI technique.
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Objective:To investigate the benefits of artificial intelligence (AI)-based image optimization technique on image quality of coronary CT angiography (CCTA).Methods:Sixty patients, who were referred for CCTA, were prospectively enrolled between May and June 2018 in Peking Union Medical College Hospital and were randomly divided into two groups. Group A was scanned with a low tube voltage of 80 kVp and a reduced contrast media volume of lopamiro at 0.7 ml /kg and group B was scanned with a standard 120 kVp tube voltage and an injection of 70 ml lopamiro. According to the different reconstruction methods, group A was divided into two subgroups. The images of group A1 were reconstructed with iterative reconstruction (IR). IR and further AI-based image optimization were used in group A2. Group B was also reconstructed by IR. To evaluate image quality objectively, the mean attenuation of contrast-enhancement values, background noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were measured and calculated in the region of interests (ROIs) of the aortic root (Ao), left main coronary artery (LM), left anterior descending branch (LAD), left circumflex branch (LCX) and right coronary artery (RCA), respectively. In addition, the subjective evaluation was performed by two radiologists using Likert 4 scale (1 for excellent and 4 for poor) to evaluate the image quality of coronary artery branches and segments. The estimated radiation dose in terms of volume CT dose index (CTDI vol), dose length product (DLP) and effective dose (ED) was recorded and compared between group A and group B. Analyses of the differences between groups were compared with image quality, radiation dose by t test or Wilcoxon signed ranks test, and subjective assessments were compares with χ 2 test. Results:In terms of lumen enhancement, compared to group A2, there was no significant difference in CT value of each ROI ( P>0.05); CT value of group A1 and group A2 at Ao was significantly higher than that of group B ( P<0.01), but there was no significant difference in other ROI ( P>0.05). By comparing noise, SNR and CNR, it could be seen that compared to group B, A2 group optimized by AI had a significantly lower noise level at Ao than group B ( P<0.001), and there was no statistical difference in ROI for the rest (all P>0.05).SNR at Ao was significantly higher than that of group B ( P<0.001), and there was no statistical difference in ROI for the rest ( P>0.05).However, the CNR of group A2 was significantly higher than that of group B in all ROI ( P<0.001). Compared to the AI-optimized A2 group, the noise of A2 group was significantly lower than that of A1 group at all ROI, and SNR and CNR were significantly higher than that of A1 group ( P<0.001). The subjective evaluation results of coronary segments showed that image quality of group A2 and group B was significantly better than that of group A1 ( P=0.002,0.038). There was no significant difference between group A2 and group B ( P=0.543). The radiation dose indexes of CTDI vol, DLP and ED in group A were significantly lower than those in group B (all P<0.001). The ED was decreased by 70.4%. Meanwhile, the volume of contrast media in group A was reduced by 37.1% than that that in group B. Conclusion:Compared to conventional scanning, CCTA images optimized by AI technology improved subjective and objective image quality.
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Objective:To evaluate the feasibility of high concentrated contrast media combined with monochromatic images to improve image quality with double low scanning in dual-layer spectral coronary CT angiography.Methods:Fifty-six patients with suspected coronary artery disease were enrolled and randomly separated into two groups. All patients were scanned at 120 kVp in step-and-shoot mode using a dual-layer detector CT (IQon spectral CT). Patients were either injected with 18 ml high concentration contrast medium(400 mgl/ml) at 2 ml/s (group A) or 45 ml contrast medium (370 mgl/ml) at 4 ml/s (group B). Forty to 80 keV monoenergetic images with 10 keV increment and conventional image (group A2) were reconstructed for group A, conventional poly-energetic image was reconstructed for group B. Region of interest was placed on aorta root (AO), middle segment of left anterior descending (LAD), left circumflex (LCX) and right coronary artery (RCA) to measure the attenuation and noise, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Image quality was assessed by two reviewers independently with a 4-point scale on image quality (1-undiagnostic,4-excellent). The objective and subjective image evaluation were compared using the Kruskal-Wallis test. The Steel Dwass was used for multiple comparisons between monoenergetic images in Group A and conventional images in Group B, after the Kruskal-Wallis test.Results:There were significant differences among the attenuation, noise, SNR and CNR of group B, group A2, and monoenergetic images(all P<0.001).The CT value in the aortic root was significantly higher at 40-50 keV monoenergetic images than that in group B(all P<0.05), and similarly, the CT value in LAD,LCX and RCA at 40 keV were superior than that in group B(all P<0.001). There was no significant difference in the noise of the aortic root among 40 keV image, group A2 and group B(all P>0.05),while the noise in the 50-80 keV monoenergetic images were significantly lower than that in Group B(all P<0.001). The SNR and CNR in the aortic root were significantly higher at 40-60 keV monoenergetic images than that in group B(all P<0.001).The SNR in LAD and RCA at 40,50 keV and the CNR in LAD and RCA at 40-60 keV were higher than that in group B(all P<0.01).The SNR at 40-60 keV and CNR at 40-70 keV in LCX were superior than that in group B(all P<0.05). There were significant differences among the subjective image quality score of group B, group A2, and monoenergetic images(all P<0.001).The subjective image quality score of 40,50 keV images were not significantly different from that in group B (all P>0.05),while the score in 60-80 keV image and group A2 were lower than that of Group B(all P<0.001). Conclusion:40,50 keV low monochromatic images derived from dual-layer spectral detect CT combined with high concentrated contrast media can provide comparable or superior image quality with double low scanning in CCTA study.
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Objective:To provide more options for preoperative localization diagnosis in patients with primary hyperparathyroidism (PHPT), the diagnostic efficacy of parathyroid 4-dimensional computed tomography (4D-CT) in patients with PHPT was evaluated.Methods:This was a single-center retrospective study including 57 patients with surgical proved PHPT. All of the patients underwent 4D-CT, 99Tc m -sestamibi parathyroid imaging (MIBI), and ultrasonography (US) preoperatively. The reference standard for correct localization was based on operation reports and pathology confirmation. The patients were grouped according to the preoperative serum calcium levels, tumor diameter, or ectopic lesions (yes/no), respectively. The sensitivity, specificity, positive predictive value, negative predictive value and area under the curve (AUC) of 4D-CT, MIBI and US, alone or in combination, were analyzed in total and each subgroup patients. Results:Fifty-seven patients (39 women, 18 men; mean age of 56.5 years) were evaluated, including four cases with multi-gland disease and thirteen cases with ectopic parathyroid lesions. In all the patients, similar diagnostic efficacy was found in 4D-CT (AUC: 0.943) and MIBI (AUC: 0.927), both of which were higher than that of US (AUC: 0.847) ( P = 0.01 for 4D-CT vs. US; P = 0.04 for MIBI vs. US). In a subset analysis for ectopic quadrants, the diagnostic efficacy of 4D-CT was significantly higher than that of MIBI ( P = 0.04) or US ( P = 0.01), with the sensitivity of 100%, 69.2%, and 61.5%, and AUC of 0.989, 0.846, and 0.808 for 4D-CT, MIBI and US, respectively. Conclusions:4D-CT has similar diagnostic efficacy for preoperative localization to MIBI in patients with PHPT, and it is superior to MIBI and US in identifying the ectopic parathyroid gland. 4D-CT can be recommended as an alternative preoperative localization method, especially when parathyroid lesions could not be precisely located by US and MIBI.
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Objective@#To explore the application value of 3.0 T MultiVane XD (MVXD) technique in female patients with uterine adenomyosis and fibroids.@*Methods@#Patients diagnosed with uterine fibroids with ultrasound and suspected of adenomyosis were involved prospectively from March to May 2018, 3.0 T pelvic MRI examinations were performed during peri-ovulatory period. Axialconventional turbo spin echo (TSE) T2WI, axial MVXD T2WI, sagittal conventional TSE T2WI and MVXD sagittal T2WI were acquired. Two observers rated those 4 series in the aspects of sharpness of uterine border, motion artifacts, identification capability of lesions, confidence of diagnosis and overall image quality. Cohen Kappa analysis was used to evaluate the consistency of scores between 2 observers. Scores of TSE T2WI and MVXD T2WI qualities were compared using Wilcoxon matched-pairs signed-ranks test.@*Results@#Twenty patients were enrolled. Axial conventional TSE T2WI, axial MVXD T2WI were aquired on all of them. Sagittal conventional TSE T2WI, sagittal MVXD T2WI were aquired on 19 among them. Nine patients had only obvious adenomyosis, 6 had only uterinefibroids, and 5 had adenomyosis and uterine fibroids. Compared to conventional TSE technique, scores of two observers in the sharpness of uterine border, motion artifacts, and overall image quality is higher by MVXD with significant difference (P<0.05). The Kappa values for image quality scores of two observers ranged from 0.615 to 0.971, the agreement was good or very good.@*Conclusion@#Applying MVXD T2WI technique to patients with uterine fibroids and adenomyosiscould improve image quality, without sacrificing the ability to recognize and diagnose lesions, compared to conventional TSE T2WI technique.
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To summarize the clinical characteristics and chest CT findings of coronavirus disease 2019(COVID-19)patients in Peking Union Medical College Hospital(PUMCH). A total of 13 patients with COVID-19 confirmed at PUMCH from January 20 to February 6,2020 were selected as the research subjects.Their epidemiological histories,clinical characteristics,laboratory tests,and chest CT findings were analyzed retrospectively.The location,distribution,density,and other accompanying signs of abnormal lung CT lesions were recorded,and the clinical types of these patients were assessed. The clinical type was "common type" in all these 13 patients aged(46.8±14.7)years(range:27-68 years).Ten patients had a travel history to Wuhan or direct contact with patients from Wuhan,2 cases had recent travel histories,and 1 case had a travel history to Beijing suburb.The white blood cell(WBC)count was normal or decreased in 92.3% of the patients and the lymphocyte count decreased in 15.4% of the patients.Twelve patients(92.3%)had a fever,among whom 11 patients were admitted due to fever and 2 patients(15.4%)had low fever.Eight patients(61.5%)had dry cough.The CT findings in these 13 patients were all abnormal.The lesions were mainly distributed along the bronchi and under the pleura.The lesions were relatively limited in 8 patients(affecting 1-3 lobes,predominantly in the right or left lower lobe),and diffuse multiple lesions of bilateral lungs were seen in 5 patients.The CT findings mainly included ground glass opacities(GGOs)(=10,76.9%),focal consolidation within GGOs(=7,53.8%),thickened vascular bundle passing through the lesions(=10,76.9%),bronchial wall thickening(=12,92.3%),air bronchogram(=10,76.9%),vacuole signs in the lesions(=7,53.8%),fine reticulation and interlobular septal thickening(=3,23.1%),reversed halo-sign(=2,15.4%),crazy-paving pattern(=2,15.4%),and pleural effusion(=2,15.4%). Most of our patients diagnosed with COVID-19 at PUMCH had a travel history to Wuhan or direct contact with patients from Wuhan.The first symptoms of COVID-19 mainly include fever and dry cough,along with normal or reduced counts of WBC and lymphocytes.CT may reveal that the lesions distribute along the bronchi and under the pleura;they are typically localized GGOs in the early stage but can become multiple GGOs and infiltrative consolidation in both lungs in the advanced stage.Scattered vacuole signs may be visible inside the lesions in some patients.
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Adulto , Idoso , Humanos , Pessoa de Meia-Idade , Betacoronavirus , Infecções por Coronavirus , Diagnóstico por Imagem , Pulmão , Pandemias , Pneumonia Viral , Diagnóstico por Imagem , Estudos Retrospectivos , Tomografia Computadorizada por Raios XRESUMO
OBJECTIVES: To evaluate the effect of different ranges of systolic blood pressure (SBP) on left ventricular (LV) geometry and diastolic function in Chinese population. DESIGN: Cross-sectional study. SETTING: Peking Union Medical College Hospital in Beijing, China. PARTICIPANTS: All inhabitants aged 35 years or older, living in five villages of Shunyi were invited. Exclusion criteria included individuals who declined participation, presence of moderate to severe valvular heart disease, persistent atrial fibrillation and suboptimal echocardiograms. INTERVENTIONS: The baseline data of 1051 participants were analysed. The relationship between SBP and LV geometric and diastolic function assessed by echocardiography was analysed after adjusting for conventional cardiac risk factors. RESULTS: The adjusted value of SBP was independently associated with LV hypertrophy (LVH) and LV diastolic dysfunction (LVDDF) (all p<0.01). Setting individuals with SBP <120 mm Hg as the reference group (group 1), those with SBP between 120 mm Hg and 140 mm Hg (group 2) had higher risk odds of LVH and those with SBP ≥140 mm Hg (group 3) had higher risk odds of LVH and LVDDF (all p<0.01). With the increase of SBP, LV mass index (LVMI) and E/e' stepwise increased and e' stepwise decreased significantly from group 1 to 3 (all p<0.05). In the whole population, SBP was independently correlated with LVMI, LVEDD, Left Atrial Volume Index, e', and E/e' (all p<0.01). CONCLUSIONS: SBP was independently related to LVH and LVDDF, SBP between 120 and 140 mm Hg was independently related to worse LV remodelling and diastolic function, these findings indicated the potential benefit of intensive SBP control.
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Pressão Sanguínea , Hipertensão/epidemiologia , Hipertrofia Ventricular Esquerda/epidemiologia , Disfunção Ventricular Esquerda/epidemiologia , Adulto , Idoso , Causalidade , China/epidemiologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Remodelação VentricularRESUMO
Objective@#To explore the value of quantitative CT radiomics features in predicting the anaplastic lymphoma kinase (ALK) mutation status in lung adenocarcinoma patients.@*Methods@#This retrospective study reviewed one hundred and ninety-five lung adenocarcinoma patients (including 60 patients with ALK mutation) whose ALK genetic test results were available from Nov 2015 to May 2018 in PUMCH. VOIs were labeled by an automatic pulmonary nodule detection and segmentation algorithm and were later revised and confirmed by two senior radiologists. The PyRadiomics tools were used to resample the labeled regions, followed by image pre-processing (Wavelet filter or Laplacian of Gaussian (LoG) filter) and feature extraction. Normalized features were selected based on their representativeness on Dr. Wise research platform. Multivariate logistic regression was performed to develop prediction models of ALK mutation gene based on different image pre-processing techniques and different radiomics feature types. The results were validated by ten runs of five-fold cross validation. ROC curve analysis and Delong test were used to compare the predictive performance among models.@*Results@#Fifteen radiomics features with the highest representativeness were selected from the original 1 232 features. The prediction model based on these radiomics features showed good performance (AUC=0.88 in the training set and 0.78 in the validation set) and was not significantly different from the prediction models based on radiomics features of different pre-processing images (AUC=0.76, P=0.1, original CT images; AUC=0.75, P=0.3, Wavelet-filtered images; AUC=0.76, P=0.2, LoG-filtered images). Among the models built with radiomics features of different types, the one based on GLCM feature (a subtype of texture feature) showed the best performance in predicting ALK genetic status (AUC=0.83, accuracy=0.74, sensitivity=0.85 and specificity=0.69). The model based on first-order statistic features had an AUC of 0.80.@*Conclusion@#Quantitative CT radiomics features have a good potential to anticipate the expression of ALK fused gene in patients with lung adenocarcinoma.
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Objective To investigate the clinical,therapeutic and prognostic features of patients with lateral sinus stenosis and isolated intracranial hypertension,and further explore the possible mechanisms of their coexistence.Methods We retrospectively enrolled 16 patients with neurosurgery in our hospital from January 2009 to December 2016,who were clinically diagnosed as simple intracranial hypertension with bilateral or predominant lateral sinus stenosis and lateral stenting.These 16 patients were recorded surgical procedures and postoperative outcomes,and followed-up to understand the long-term prognosis of them.Results There were 14 females in the 16 patients,with an average age of (32.4 ± 10.1) years,a mean duration of (10.9 ± 7.3) months,and an average body mass index of (28.9 ± 3.6) kg/m2.In terms of clinical manifestions,majority of the patients presented with headache (n =15) and visual symptoms (n =14),and all with papilledema by fundus examination.The elevated opening cerebrospinal fluid (CSF) pressure was noticed:five cases between 25-33 cmH2O (1 cmH2O =0.098 kPa),11 cases more than 33 cmH2O.The mean pressure difference in the proximal and distal sinus of the anterior chamber was (36.3 ± 9.4) cmH2O in the range of 15-91 cmH2O.The pressure difference between the two ends of the stenosis disappeared immediately after the operation in 12 cases and the pressure difference less than 15 (2-12) cmH2O in four cases.Thirteen patients underwent lumbar puncture at one week after operation.The CSF pressure of them decreased significantly,of which eight were in the normal range.Six months after the operation,11 patients underwent DSA/MRV,none of which had serious surgical complications.With the average follow-up of (35.4 ± 9.8) months,the overall prognosis of these patients was good.Headaches in 14 of 15 patients were improved,out of which 12 were free of headache,two with only mild headache and a slight intracranial hypertension (19 and 23 cmH2O,respectively);visual complaints were reversed in nine out of 14 cases;10 patients underwent fundus examination,and nine of them were observed the improvement of papilledema.During the follow-up period,the symptoms of other patients were improved (headache relief and visual improvement) except one,the overall effective ratio being 15/16.Conclusions The interventional treatment of lateral sinus stenting is effective in patients with sinus stenosis associated with simple intracranial hypertension.The stenosis of the lateral sinus may be the main mechanism of increased intracranial pressure.
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Objective To explore the impact of antiplatelet agents on the occurrence of hemorrhage after percutaneous nephrostomy (PCN).Methods Totally 197 patients (244 kidneys) underwent PCN were enrolled and divided into postoperative hemorrhage group and without postoperative hemorrhage group.The possible factors of the postoperative hemorrhage were analyzed.Results Post-operative hemorrhage occurred in 23 patients with 27 kidneys (27/244,11.07%).Univariate analysis showed that except for antiplatelet drugs,the other factors had no statistical difference between the two groups (P>0.05).Logistic regression analysis showed that taking dual-antiplatelet was the risk factor of hemorrhage after PCN (OR=12.381,P =0.002).Conclusion Single aspirin therapy can not increase the risk of hemorrhage after PCN,while taking dual-antiplatelet might increase the risk of hemorrhage.Normal clotting function is also a guarantee of preventing hemorrhage after PCN.