Objective To explore the image quality and radiation dose for coronary angiography using DSCT (dual-source computed tomography) under lower tube voltage and lower contrast agent concentration ('double low').Methods A total of 160 patients with suspected coronary artery disease underwent dual-source CCTA.80 patients (BMI ＜ 25 kg/m2) were randomly assigned to group A (270 mg I/ml-80 kV) and B (350 mg I/ml-120 kV).The other 80 patients (25 ≤ BMI ＜30 kg/m2) were randomly assigned to group C (270 mg I/ml-100 kV) and D (350 mg I/ml-120 kV),sonogram affirmed iterative reconstruction technology and 270 mg I/ml contrast agent were applied to group A and C ; FBP technology and 350 mg I/ml contrast agent were applied to group B and D.Adaptive cardio-sequence prospective ECG-gated technology was applied in all patients,while the acquisition phase was 65％-75％ RR interval (when heart rate ＜ 75 beats / min) or 40％-50％ RR interval at when heart rate ≥ 75 beats/min.Volume CT dose index (CTDIvol),dose length product (DLP),effective dose (E),size specific dose estimates (SSDE),image noise,CT value,signal-to-noise ratio (SNR),and contrast-to-noise ratio(CNR) were all evaluated for each patient.Results There was not statistical difference in scan length among groups A and B,C and D.There was statistical difference in tube current between group A and B (t =8.932,P ＜0.05).There was not statistical difference in tube current between group C and D (tCD =-1.212,P ＞ 0.05).There was statistical difference in CTDIvol,DLP,E and SSDE between group A and B,C and D (tCTDIvol =-16.141,-11.440 ; tDLP =-17.454,-10.521 ; t =-17.444,-10.523 ;tSSDE =-13.032,-9.119,P ＜0.05).Compared to group B,the SSDE in group A decreased by 64.4％.Compared to group D,the SSDE in group C decreased by 39.3％.There was no statistical difference in image noise between group A and B,C and D (P ＞ 0.05).There was statistical difference in CT value,SNR and CNR between group A and B (t =0.436,4.623,3.272,P ＜ 0.05).There was no statistical difference in CT value and CNR between group C and D,while there was statistical difference in SNR between group C and D (t =2.981,P ＜0.05).There was no statistical difference in image quality scores between group A and B,C and D (P ＞ 0.05).Conclusion Compared with conventional DSCT coronary angiography,'double low' DSCT coronary scanning solution can significantly reduce the radiation dose and contrast agent,and could provide the effective coronary images which meet the clinical diagnostic needs.

Objective To explore the feasibility of “double low ”(low tube voltage and low contrast agent concentration)imaging technology of dual-source computed tomography (DSCT)in coronary angiography for low-weight patients.Methods 60 patients (BMI≤25 kg/m2 )who underwent coronary CT angiography (CCTA)on DSCT scanner were divided randomly into 2 groups:group A was “double low”group (n = 30,tube voltage = 80 kVp,using sinogram affirmed iterative reconstruction technology and 270 mg I/mL concentration of contrast agent);Group B was conventional group (n=30,tube voltage=120 kVp,using filtered back projection technology and 350 mg I/mL concentration of contrast agent).Adaptive cardiosequence prospective ECG-gated technology (CorAdSeq)was applied in both the groups,The collecting phase was 65%-75% RR interval (when heart rate<70 beats per mi-nute)or 40%-50% RR interval (when heart rate≥70 beats per minute).Subjective and objective methods were applied to evaluate the image quality.The image quality and.radiation dose were compared between the “double low”group and the conventional group by using SPSS 1 9.0 software.The differences between measurement data were analyzed by using independent samples t-test.Results The effective dose with size specific dose estimates (EDssde)of group A(1.22±0.31)mGy/cm was significantly lower than that of group B (3.44±0.80)mGy/cm with P <0.001.Contrast-noise ratio,signal-noise ratio and CT value of group A were signifi-cantly higher than those of group B (all P <0.05 ).Conclusion Compared with conventional DSCT coronary angiography,“double low”DSCT coronary scanning proposal for low-weight patients can significantly reduce the radiation dose and the amount of contrast agent,and the image quality can meet the needs of clinical diagnosis.

Objective To compare the iodine intake,image quality and radiation dose of dual-source CT coronary artery angiography between the low concentration isotonic contrast agent with iterative reconstruction technique of sinogram affirmed iterative rEconstruction (SAFIRE) and common concentration contrast agent with filtered back projection (FBP).Methods One hundred patients [58 men,42 women; age:(62± 11)y] were enrolled in this study.Fifty consecutive patients (Group A) were scanned with FBP and common concentration contrast agent and another 50 consecutive patients (Group B) were scanned with low concentration isotonic contrast agent and iterative reconstruction technique.The image quality were assessed by two experienced radiologists with a double blinded fashion in a five score scale.The attenuation of coronary artery,scan time,imaging noise,signal-to-noise ratio (SNR),contrast-to-noise ratio (CNR),radiation dose and iodine intake between these two groups were compared using two sample t test.The observer agreement for image quality was calculated using Kappa statistics.Results All examinations were completed successfully.There was no statistical difference (P＞0.05) between two groups in clinical characteristics and scan parameters.There was no statistical difference for the mean subjective image quality of group A (4.4±0.7) and group B (4.3±0.8) (t=0.924,P＞0.05).The Kappa value between two radiologists was 0.887 (P＜0.01)on image quality.The mean attenuation of coronary artery segments was higher than 300 HU,especially in group A (386.1±51.5) HU,which was slightly higher than the group B (384.1±77.1) HU,but there was no statistical difference (t=0.157,P＞0.05).The SNR and CNR in two groups did not have significant differences (P＞0.05).The total iodine and iodine injection rates were 21.0 g,17.5 g/s in Group A and 16.2 g,13.5 g/s in Group B,respectively.The iodine intake was decreased by 22.9％ in Group B.The effective radiation dose in Group B (1.09±0.19) mSv was significantly (t=20.260,P＜0.01) lower than that in Group A (2.85±0.59) mSv,with the radiation dose reduced by 61.8％.Conclusion Low concentration isotonic contrast agent and iterative reconstruction technique can significantly reduce the radiation dose and iodine intake in CT coronary artery angiography and achieve the same image quality using common concentration contrast agent with FBP.

Objective To explore the accuracy and radiation dose of the right ventricular analysis with DSCT(dual-source computed tomography)using dual-step prospective ECG trigger.Methods Fortyeight consecutive patients who were suspected or diagnosed with coronary artery disease were examined with DSCT coronary angiography and MRI ventricular analysis.Sequential acquisition and dual-step prospective ECG-trigger were used with 30％-90％ width R-R interval.Full tube current output was adopted at 70％ (HR ≤70 bpm)or 40％ (HR ＞ 70 bpm) R-R interval according to heart rates,while 20％ current output was adopted in other R-R interval.Coronary artery was divided into 16 segments according to the American Heart Association.Image quality of coronary arteries were graded with 4-points scale.The DSCT date was reconstructed with 5％ R-R interval.RVESV,RVEDV and RVEF were evaluated in DSCT and MRI.Results Forty-two cases accomplished DSCT and MRI examination.In 558 evaluated coronary segments,96.42％ could be diagnosed.The average radiation dose was(2.82 ± 0.55)mSy.Paired t-test indicated that the RVESV,RVEDV and RVEF of DSCT and MRI had no statistically significant differences (t =-0.28,0.44 and 1.49,P＞0.05),and the correlation was high (r =0.89,0.89,0.87).Conclusions The two generation DSCT with dual-step prospective ECG-triggered sequential acquisition can be used in coronary angiography and right ventricular function analysis simultaneously,which is high in imaging quality of coronary artery,reliable in right ventricular function analysis,as well as lower in radiation dose.

Objective To investigate the value of procalcitonin (PCT) for urosepsis secondary to ureteral calculus.Methods Samples of 68 ureteral calculi patients who were suspected of urosepsis were obtained for PCT level,C-reactive protein (CRP) level,blood routine examination,urinary sediment,blood culture and urine culture.Sixty-eighy patients were divided into urosepsis group and non-urosepsis group based on the urosepsis diagnostic standard.The age sex,stone location,stone size,blood WBC count,CRP level,PCT level and urine WBC count were compared between the 2 groups.PCT levels before and after treatment were also compared.Results The age,stone size in urosepsis group were significantly higher than those in non-urosepsis group.The PCT levels of patients in urosepsis group and non-urosepsis group were 19.09±25.15 μg/L and 2.09± 1.85 μg/L respectively before treatment,and there was a significant difference between the 2 groups (P＜0.05).The blood WBC counts (× 109/L) of patients in urosepsis group and non-urosepsis group were 11.00± 3.47 and 10.27±2.32 respectively before treatment (P＞0.05).The CRP levels of patients in urosepsis group and non-urosepsis group were 17.41±15.24 mg/L and 15.02±4.94 mg/L respectively before treatment (P＞0.05).The median urine WBC counts (per HPF) of patients in urosepsis group and non-urosepsis group were 54 and 47 respectively before treatment (P＞0.05).The PCT levels of patients in urosepsis group before and after treatment were 19.09 ± 25.15 μg/L and 1.06 ± 0.56 μg/L,and there was a significant difference (P＜0.05).Conclusion PCT has a definite value for early diagnosis of urosepsis,condition assessment and treatment guideline.

Objective To evaluate the prognostic significance of carbonic anhydrase IX (CA IX) expression in patients with clear cell renal cell carcinoma (ccRCC). Methods CA IX expression in a cohort of 120 patients with ccRCC was evaluated by P-V immunohistochemistry with a rabbit CA IX polyclonal antibody. Twenty-five normal kidney tissues were used as a control. The relationship between CA IX expression and prognosis was analyzed by univariate and multiple-factor analysis (Cox regression model). The primary end point was cancer specific survival. Results One hundred and twelve (93.3%) patients were followed up with the median follow-up time of 45 months (range, 6 to 94 months). Seventy-five patients survived without evidence of tumor recurrence, 3 patients survived with tumor recurrence, and 34 patients died, 28 of the 34 died of cancer. CA IX expression was negative in all normal renal tissue. High CA IX expression was observed in 89 (74.2%) patients, among which 82 patients were followed up, and the disease free survival was 75.6% (62/82). Two (2.4%) patients survived with tumor recurrence, and 18 (22.0%) patients died, of which 13 (15.9%) died of cancer. Tumor recurrence and (or) metastasis occurred in 9 (11.0%) patients, with a median survival of 92 months in this high expression group. Low CA IX expression was observed in 31 (25.8%) patients, among which 30 patients were followed up, and the disease free survival was 43.3% (13/30). One (3.3%) patient survived with tumor recurrence, and 16 (53.3%) patients died, of which 15 (50.0%) died of cancer. Tumor recurrence and (or) metastasis occurred in 8 (26.7%) patients with a median survival of 53 months in this low expression group. Cancer specific survival between CA IX high expression group and low expression group was significantly different (P=0.000, χ2=15.950), and tumor relapse and (or) metastasis rates were significantly different (P=0.040, χ2=4.200). The 1, 3, 5 and 7 year cancer specific survival rates were 95.2%, 83.9%, 81.2% and 78.2% respectively in the high CA IX expression group, and 89.5%, 63.9%, 46.8% and 40.1% respectively in the low expression group. Multivariate analysis with Cox regression model showed that CA IX expression was a prognostic factor (RR=0.186). Conclusions High CA IX expression is negatively correlated with postoperative mortality, relapse and (or) metastasis in ccRCC. CA IX expression could be used as a prognostic biomarker in ccRCC.

Objective To determine the predictive parameters of impacted ureteral stones and evaluate the predictive value of ureteral wall thickness for impacted ureteral stones.Methods A total of 93 patients with proximal ureteral stones from January 2017 to December 2017 were included in the study [71 males and 22 females,aged 30-80 years,and body mass index (23.7 ± 2.7) kg/m2].Both clinical and computed tomography urography (CTU) data were compared between patients with or without impacted ureteral stone,including sex,age,body mass index,renal pelvic diameter,longitudinal size of stone,transverse size of stone,stone surface area,stone volume,hounsfield units of stone,diameter of the ureter proximal to the stone,and ureteral wall thickness at the impacted ureteral stone site.The receiver operating characteristic curve (ROC) was used to analyze the performance of each of the above-mentioned parameters for predicting the impacted ureteral stones.Multivariate logistic regression analysis was used to select the independent risk factors of impacted ureteral stones.Results Among 93 patients,38 (40.8％) patients were with impacted stones and 55 (59.1％) without impacted stones.Univariate analysis showed significant difference in ureteral wall thickness (t =6.344,P ＜ 0.001),diameter of the ureter proximal to the stone (U =607.5,P =0.001),longitudinal size of stone(U =580.5,P ＜0.001),transverse size of stone(t =4.172,P ＜0.001),stone surface area(U =508.5,P ＜ 0.001),stone volume (U =508.5,P ＜ 0.001) and hounsfield units of stone (t =6.344,P =0.006) between patients with or without impacted stones.Ureteral wall thickness(UWT)showed the largest area under curve (AUC) among those parameters (AUC =0.825,P ＜ 0.001),followed by stone surface area and stone volume.The optimal cut-off value of ureteral wall thickness was 3.16 mm,with sensitivity of 71.1％ and specificity of 85.5％.Multivariate analysis showed that ureteral wall thickness (Wald =18.709,P ＜ 0.001) and stone volume (Wald =8.391,P =0.004) were independent predictors of impacted stones.Conclusion Ureteral wall thickness was related to the presence of impacted ureteral stones and could be used for predicting impacted ureteral stones.