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Objective:To investigate the value of radiomics in image quality control with low-dose CT examination of solid pulmonary nodules.Methods:Images were acquired on CT750 HD scanner, and chest pulmonary nodules phantom were scanned at different tube voltage and tube current. The radiation dose CTDI vol under different scanning conditions were recorded, as well as CNR and SNR of each scanning sequence. The variation of radiation dose, noise, tube voltage and tube current were analyzed. All data were analyzed by radiomics analysis software. R language statistics software was adopted to analyze the extracted features by principal component analysis (PCA), and the characteristic parameters with the largest contribution rate to image quality were selected for analysis. One-way ANOVA was used to analyze all the important characteristic parameters to reveal the difference of characteristic parameters under different tube voltages. Finally, the post-test method was used to find out the differences among different tube voltage groups. Results:Radiation dose rised linearly with the increase of tube current and tube voltage. Although the overall change trend of SNR and CNR in pulmonary nodules was linearly related to the change of tube voltage and tube current, there was no clear change trend threshold at low dose, which could not accurately evaluate the image quality under low radiation. Both CNR and SNR cannot evaluate the image quality effectively, and have no practiced value for optimizing the low dose scanning parameters. There main components including Uniformity, Voxel Value Sum, and Haralick Correlation extracted by radiomics analysis software were proved to play a critical role in image quality control. The cumulative contribution rate of variance was 89.20% and the eigen values were greater than 1. Uniformity curve of characteristic parameter showed that the trend of change was correlated with the change of tube voltage and tube current, and the stability and consistency were good. Uniformity one-way ANOVA analysis showed that when the tube voltage reduced from 140 to 120 kVp, there was no difference ( P=0.117) in the uniformity, while from 120 to 80 kVp, significant differences revealed ( P<0.001). Considering tube current, no significant variation was observed in uniformity when current was greater than 90 mA, which indicated that tube current of 90 mA could lead to better image quality. Conclusion:Radiomics analysis can effectively evaluate and control the CT image quality of low dose solid pulmonary nodules.
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Objective@#To investigate the value of radiomics in image quality control with low-dose CT examination of solid pulmonary nodules.@*Methods@#Images were acquired on CT750 HD scanner, and chest pulmonary nodules phantom were scanned at different tube voltage and tube current. The radiation dose CTDIvol under different scanning conditions were recorded, as well as CNR and SNR of each scanning sequence. The variation of radiation dose, noise, tube voltage and tube current were analyzed. All data were analyzed by radiomics analysis software. R language statistics software was adopted to analyze the extracted features by principal component analysis (PCA), and the characteristic parameters with the largest contribution rate to image quality were selected for analysis. One-way ANOVA was used to analyze all the important characteristic parameters to reveal the difference of characteristic parameters under different tube voltages. Finally, the post-test method was used to find out the differences among different tube voltage groups.@*Results@#Radiation dose rised linearly with the increase of tube current and tube voltage. Although the overall change trend of SNR and CNR in pulmonary nodules was linearly related to the change of tube voltage and tube current, there was no clear change trend threshold at low dose, which could not accurately evaluate the image quality under low radiation. Both CNR and SNR cannot evaluate the image quality effectively, and have no practiced value for optimizing the low dose scanning parameters. There main components including Uniformity, Voxel Value Sum, and Haralick Correlation extracted by radiomics analysis software were proved to play a critical role in image quality control. The cumulative contribution rate of variance was 89.20% and the eigen values were greater than 1. Uniformity curve of characteristic parameter showed that the trend of change was correlated with the change of tube voltage and tube current, and the stability and consistency were good. Uniformity one-way ANOVA analysis showed that when the tube voltage reduced from 140 to 120 kVp, there was no difference (P=0.117) in the uniformity, while from 120 to 80 kVp, significant differences revealed (P<0.001). Considering tube current, no significant variation was observed in uniformity when current was greater than 90 mA, which indicated that tube current of 90 mA could lead to better image quality.@*Conclusion@#Radiomics analysis can effectively evaluate and control the CT image quality of low dose solid pulmonary nodules.
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Objective To evaluate the accuracy of cone?beam breast CT (CBBCT) on tumor sizing in patients with invasive breast carcinoma and analyze the influence factors. Methods The preoperative CBBCT images of 82 female patients (85 breast lesions) with invasive breast carcinoma confirmed by pathology from November, 2011 to December, 2017 in Tianjin Medical University Cancer Hospital were included in this retrospective study. All the patients underwent the pathology and immunohistochemical test after operation. Tumor size estimation were performed on preoperative CBBCT images. Referring to tumor size measurement on pathology, all the lesions were divided into two groups. Concordance was defined as the discrepancy in diameter less than 0.5 cm, and the discordance was more than 0.5 cm. Pathology examination was performed after resection, and estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2(HER?2) and Ki?67 result were recorded. All the lesions were classified into molecular subtype, including 14 Luminal A, 50 Luminal B, 11 HER?2?enriched and 10 triple?negative. Intraclass correlation coefficient (ICC) and Pearson correlation coefficient were used to analyze the reliability of CBBCT on tumor sizing. CBBCT?pathology discordance was analyzed based on the clinical, histopathology and CBBCT features by using t test, Chi?square and Fisher exact test. ROC curve was used to analyze the cut?off value between tumor size and CBBCT?pathology discordance. Results The agreement between CBBCT (2.155 ± 0.799) cm and pathology (1.986 ± 0.933) cm measurement was on moderate degree based on the ICC value (ICC=0.781, P<0.01) and had positive correlation (r=0.803, P<0.01). CBBCT?pathology concordance was found in 71 lesions, and discordance in 14 lesions. The factors of family history, symptom, pathology type, molecular subtypes, histological grade, surrounding fat invasion, lymphatic invasion, axillary lymph node metastasis, HER?2 positive and Ki?67 high expression had no significant difference between two groups. ER or PR positive had significant difference, suggesting that the accuracy of evaluation on ER or PR negative lesions could be reduced. The cut?off value of ROC curve between tumor size and CBBCT?pathology discordance was 2.08 cm, and the area under curve was 0.70. In 85 lesions. 66 of 75 mass lesions and 5 of 10 non?mass lesions were consistent. The lesion type had significant difference between two groups (χ2=6.705, P=0.010), which suggested the CBBCT evaluation on non?mass could have discrepancy with pathology. Conclusion CBBCT has high accuracy on tumor size evaluation on invasive carcinoma. ER or PR negative, large lesions or non?tumor lesions should be alert to the impact of CBBCT?pathology discordance before surgery which may cause the alteration of surgical protocols.
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Objective@#To compare the diagnostic efficiency of lesion in dense breast between cone beam breast computer tomography (CBBCT) and mammography.@*Methods@#From May 2012 to August 2014, 160 patients with 165 breasts who underwent mammography and CBBCT examinations were included in this study. The diagnostic results of CBBCT and mammography were reviewed and compared with pathological results.@*Results@#In the 165 breast, 24 were dense breasts and 141 were dense breasts. The diagnostic results were similar in 109 lesions, but different in 56 lesions. According to the analysis of the 165 breasts using receiver operation characteristics (ROC) curve, the area under the ROC curves (AUC) of CBBCT and mammography were 0.923 (95%CI: 0.878-0.967, P<0.05) and 0.959 (95%CI: 0.926-0.992, P<0.05), respectively. With Breast Imaging-Reporting and Data System (BI-RADS) 4b as the critical value, the sensitivity and specificity were 70.0% and 98.7% using mammography, and 83.3% and 97.3% using CBBCT, respectively. The AUC of CBBCT and mammography of the 141 dense breasts was 0.919(95%CI: 0.868-0.969, P<0.05) and 0.973(95%CI: 0.947-0.999, P<0.05), respectively. With BI-RADS 4b as the critical value, the sensitivity and specificity were 69.0% and 98.6% by mammography, and 83.1% and 98.6% by CBBCT, respectively.@*Conclusions@#CBBCT showed higher sensitivity and specificity in the diagnosis of breast malignant tumors compared to mammography. It is expected to be applied to breast cancer detection in the future, especially in dense breast.
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18 patients with atrioventricular nodal reentant tachycardia (AVNRT)and 5 patients with atrioventricular reentrant tachycardia (AVRT) with AVN double pathway (AVNDP) received radiofrequency ablation of slow pathway with inferior approach in order to modify AVN. AVNRT was induced in slow-fast form in 16 patients, in fast-slow form in one patients,and in coexistent slow-fast and fast-slow forms in one patients. Selective ablation of slow pathway was achieved in 18 patients. AVRT was induced in 5 patients (one obvient accessory pathway, 4 concealed accessory pathways) ,4 patients with reentrant cirucit of consisting of anterograde conduction by slow pathway of AVN and retrograde conduction by accessory pathway (AP) , one patient coexistent AVRT and AVNRT. Slow pathway in 5 patients and AP in 3 patients were successfully ablated. Junctional rhythm appeared in 21 patients during duation of discharge of radiofrequency current. No severe complicationwere noted. AVNRT in one patient recurred during a follow-up period of 1 to 15 months. The patient experienced second catheter ablation and was successed. It was suggested radlofrequency ablation of slow pathway with Inferior approach may be a method with high rate of success and less complication.