Initial Experience of the Application of Automated Tube Potential Selection Technique in High-pitch Dual-source CT Angiography of Whole Aorta Using Third-generation Dual-source CT Scanner / 中国医学科学院学报

Objective To evaluate the application of automated tube potential selection technique in high-pitch dual-source CT aortic angiography on a third-generation dual-source CT scanner. Methods Whole aorta angiography were indiated in 59 patients,who were divided into 2 groups using a simple random method:in group 1 there were 31 patients who underwent the examination with automated tube potential selection using a vascular setting with a preferred image quality of 288 mA/100 kV;in group 2 there were 28 patients who underwent the examination with a tube voltage of 100 kV and automated tube current modulation using a reference tube current of 288 mA. Both groups were scanned on a third generation dual-source CT device operated in dual-source high-pitch ECG-gating mode with a pitch of 3.0,collimation of 2×192×0.6 mm,and a rotation time of 0.25 s. Iterative reconstruction algorithm was used. For group 1,the volume and flow of contrast medium and chasing saline were adapted to the tube voltage. For group 2,a contrast material bolus of 45 ml with a flow of 4.5 ml/s followed by a 50 ml saline chaser at 5 ml/s was used. CTA scan was automatically started using a bolus tracking technique at the level of the original part of aorta after a trigger threshold of 100 HU was reached. The start delay was set to 6 s in both groups. Effective dose (ED),signal to noise ratio (SNR),contrast to noise ratio (CNR),and subjective diagnostic quality of both groups were evaluated. Results The mean ED were 21.3% lower (t=-3.099,P=0.000) in group 1 [(2.48±0.80) mSv] than in group 2 [(3.15±0.86) mSv]. Two groups showed no significant difference in attenuation,SD,SNR,or CNR at all evaluational parts of aorta (ascending aorta,aortic arch,diaphragmatic aorta,or iliac bifurcation)(all P>0.05). There was no significant difference in subjective diagnostic quality values of two groups [(1.41±0.50) scores vs. (1.39±0.50) scores;W=828.5,P=0.837]. Conclusion Compared with automated tube current modulation,the automated tube potential selection technique in aorta CT angiography on a third-generation dual-source CT can dramatically reduce radiation dose without affecting image quality.

Initial Experience of the Application of Third-generation Dual-source CT Scanner in High-pitch Angiography of Aorta / 中国医学科学院学报

Objective To evaluate the value of third-generation dual-source CT scanner in application of high-pitch aorta CT angiography(CTA). Methods Totally 59 patients clinically indicated for whole aorta angiography were divided into 2 groups using a simple random method:in group 1 there were 28 patients who underwent the examination on a third-generation dual-source CT device,with a collimation of 2×192×0.6 mm and a rotation time of 0.25 s;in group 2 there were 31 patients who underwent the examination on a second generation dual-source CT device,with a collimation of 2×128×0.6 mm and a rotation time of 0.28 s. Both groups were given the examination operated in dual-source high-pitch ECG-gating mode with a pitch of 3.0,a tube voltage of 100 kV,and automated tube current modulation using a reference tube current of 288 mA. A contrast material bolus of 45 ml with a flow of 4.5 ml/s followed by a 50 ml saline chaser in 5.0 ml/s was used. CTA scan was automatically started using a bolus tracking technique at the level of the original part of aorta after a trigger threshold of 100 HU was reached. The start delay was set to 6 s in both groups. Effective dose(ED),signal to noise ratio (SNR),contrast to noise ratio (CNR),and subjective diagnostic quality of both groups were evaluated. Results The mean ED were 19.44% lower (t=-3.989,P=0.000) in group 1 [(3.15±0.86)mSv] than in group 2 [(3.91±0.60)mSv]. These two groups showed no significant differences in SNR or CNR (all P >0.05). The subjective diagnostic quality values also showed no significant difference between two groups [(1.39±0.50)scores vs. (1.45±0.51)scores;W=814.5,P=0.651].Conclusion Compared with the second-generation dual-source CT scanner,the third-generation dual-source CT scanner in whole aorta CTA can remarkably reduce the radiation dose without affecting image quality.

Correlation Between Dual-energy and Perfusion CT in Patients with Focal Liver Lesions Using Third-generation Dual-source CT Scanner / 中国医学科学院学报

Objective To compare measurements of dual-energy CT iodine map parameters and liver perfusion CT parameters in patients with focal liver lesions using a third-generation dual-source CT scanner. Methods Between November 2015 and August 2016,33 patients with non-cystic focal lesions of liver were enrolled in this study. CT examinations were performed with a third-generation dual-source CT. The study CT protocol included a perfusion CT and dual-energy arterial and portal venous scans,with a time interval of 15 minutes. Iodine attenuation was measured at five region of interests including areas of high,medium,and low density within the lesion,as well as right and left liver parenchyma from the iodine map,while arterial liver perfusion (ALP),portal venous liver perfusion (PVP),and hepatic perfusion index (HPI) at the same location were measured from perfusion CT. The Pearson product-moment correlation coefficient was used to evaluate the relationship between iodine attenuation and perfusion parameters. Results The iodine attenuation at arterial phase showed significant intra-individual correlation with ALP (r=0.812,95% CI=0.728-0.885,P<0.001)and PVP (r=-0.209,95% CI=-0.323--0.073,P=0.007),but not significantly correlated with HPI (r=0.058,95% CI=0.046-0.498,P=0.461). The iodine attenuation at portal venous phase showed significant correlation with PVP (r=0.214,95% CI=0.072-0.361,P=0.005) but not with HPI(r=0.036,95% CI=-0.002-0.242,P=0.649). The mean effective dose of arterial phase and portal venous phase of dual-energy CT together [(3.53±1.17)mSv] was significantly lower than that of the perfusion CT [(14.53±0.45)mSv](t=25.212,P<0.001). Conclusion Iodine attenuation from arterial phase of dual energy CT demonstrates significant correlation with ALP and PVP,and iodine attenuation from portal venous phase demonstrates significant correlation with PVP.

Feasibility Study of Low-dose Prostate CT Perfusion on Third-generation Dual-source CT / 中国医学科学院学报

Objective To investigate the feasibility of using low-dose prostate CT perfusion (pCTP)on a third-generation dual-source CT. Methods Nine patients with elevated prostate-specific antigen underwent pCTP before having prostate biopsy. We measured the blood flow (BF),blood volume (BV),mean transit time (MTT),permeability surface (PS),and time to peak(TTP)of both lesions and normal prostate tissue. The effective dose (ED)was calculated. Results Of the 9 cases,6 were prostate cancers and 3 were prostate hyperplasia with chronic inflammation. The average ED of the 9 pCTPs was (3.5±0.3)mSv. The BF (t=4.64,P<0.001),BV (t=3.27,P<0.001),and PS (t=3.58,P=0.004)of prostate cancer were significantly higher than those of normal prostate tissue and TTP (t=-1.26,P<0.001)of prostate cancer was significantly lower than that of normal prostate tissue. BF (t=3.96,P=0.001)and PS (t=2.91,P=0.021)of prostate hyperplasia with chronic inflammation were also significantly higher and TTP (t=-1.19,P<0.001)was significantly lower than those of normal prostate tissue. TTP of prostate cancer was significantly lower than that of prostate hyperplasia with chronic inflammation (t=-2.56,P=0.049). Conclusion sLow-dose pCTP is feasible on third-generation dual-source CT. The BF,PS,and TTP differ among prostate cancer,prostate hyperplasia with chronic inflammation,and normal prostate tissue.

The effect of combination treatment using iron chelator deferasirox and cisplatin on proliferation and apoptosis in non-small cell lung cancer / 天津医药

Objective To investigate the combination effect using iron chelators deferasirox and cisplatin on A549 cell proliferation and apoptosis and to provide evidences to explore an effective way to treat lung cancer. Methods Lung adeno?carcinoma cells were cultured by conventional way, with administration of different concentrations of deferasirox and cisplat?in. Cell growth inhibition was observed under an inverted microscope. Proliferation inhibition was evaluated by MTT assay. Morphological changes of cell apoptosis was detected using DAPI,AO/EB straning and flow cytometry. Results After a cer?tain time of incubation with different concentrations of the combined drugs,the cell number reduce significantly, which was counted under invert microscope. Cells were dispersed with each other and adherent cells appear shrunken and poor in re?fractivity. MTT assay showed that inhibition of cell proliferation was in a concentration-time-dependent manner. Chromatin condensation, nuclear condensation and other typical apoptotic morphology were detected after DAPI and AO/EB straning. Flow cytometry showed that apoptosis increased with rising drug concentration. So combination therapy was significantly pro-apoptotic. Conclusion Deferasirox has the ability to inhibit proliferation of A549 cells and can promote tumor cell apoptosis and enhances cancer cell tolerance when combined with cisplatin. It can also reduce the amount and toxicity of cis?platin. It provides a basis for finding an effective way to treat lung cancer.

A correlative study of CT findings and pulmonary function test in patients with SARS in the recovery phase following hospital discharge / 中华放射学杂志

Objective To evaluate the appearance of CT in patients with severe acute respiratory syndrome (SARS) in the recovery phase, and to study the correlation of CT findings with pulmonary function.Methods From June to August in 2003, 100 patient with confirmed SARS accepted examination in our hospital. Among them, 91 patients (39 men, 52 women, mean age 36.4 years, age range 19- 66 years) received CT examination and pulmonary function test on the same day. The interval between SARS onset and the examination ranged from 52 to 125 days (mean 87.4 days). CT appearances of pulmonary parenchymal abnormalities including distribution and extent of involvement were quantitatively analyzed, and four levels on CT scan including the aortic arch, the tracheal carina, the pulmonary venous confluence, and the dome of right diaphragm were selected to score the lesions. The correlation of CT scores with the results of pulmonary function tests was studied.Results Of the 91 cases, 47 patients had normal CT appearance in the recovery phase, whereas the other 44 patients still had parenchymal abnormalities, including residual ground-glass opacification and reticular shadow. CT visual score had correlation with DLco% ( r =-0.618, P

Coronary Artery Imaging in Patients with High Heart Rate by Dual-source CT:The Initial Experience / 实用放射学杂志

Objective To explore the scanning technique and image quality of coronary artery imaging with dual-source CT without oral Betaloc preparation in the patients with high heart rate.Methods 412 cases were undergone coronary imaging with dual-source CT (including plain and enhanced scans) ,among them,there were 30 cases with heart rate more than 100 bpm.Multi-planar reconstruction(MPR),maximum intensity projection(MIP) and volume rendering (VR) were performed using contrast-enhanced images.The image quality was classified into 3 grades, and coronary segments named according to AHA standard were evaluated.Results The average heart rate during enhanced scan in the 30 cases was (115.6?11.8)(101～139)bpm,the average breath hold time was (5.7?1.2) s.The best reconstruction phase was in the systolic phase. Altogether 424 coronary segments were evaluated, among them 93.9%(398/424)belonged to the first grade,5.0%(21/424)belonged to the second grade,and 1.2%(5/424) belonged to the third grade. Conclusion Without oral administration of Betaloc preparation, good coronary artery images can be obtained in the patients with high heart rate by dual-source CT.

Coronary artery imaging with dual-source CT:initial experience / 中华放射学杂志

Objective To explore the scan technique and image quality of coronary artery imaging with dual-source CT without oral Betaloc preparation.Methods Plain and enhanced dual-source CT coronary artery imaging without oral Betaloc preparation was performed in 215 patients with clinically suspected coronary heart disease or early-stage coronary lesions.Calcium scoring with plain scan images and multi-planar reconstruction(MPR),maximum intensity projection(MIP)and volume rendering technique (VRT)reconstruction with enhanced scan images were made in all cases.The scan technique and post reconstruction experience was summarized.The image quality was classified as three grades,and coronary segments classified according to AHA standards were evaluated.Results The median of calcium score of the 215 cases was 82.2(2.3—1827.9).The average heart rate of the enhanced scan was(80.6?15.3) (57—139)bpm.The post reconstruction methods with which coronary segments could be shown as best as possible consisted of(1)multiphases screening methods,(2)bi-phase or multiple-phase complement method,and(3)premature beat removing or arrhythmia shifting method.Altogether 3026 coronary segments were evaluated,among them 97.5% were evaluated as grade 1 image quality,2.0% were evaluated as grade 2 and 0.5% were evaluated as grade 3.The coronary segments in 91 cases were completely normal, while 112 segments with

Retroperitoneal fibrosis: the clinical and radiological manifestation / 中华放射学杂志

Objective To analyze the clinical and radiological features of retroperitoneal fibrosis (RPF), and to deepen the understanding of this unusual disease and improve the diagnostic level at the early stage. Methods Fourteen cases (10 males and 4 females, mean age 45.8 years) of pathologically diagnosed RPF from January 1990 to June 2004 were summarized. The clinical and radiological performance of the cases were analyzed. All patients received non-contrast CT scanning, 10 of them underwent enhanced CT scanning as well. 8 patients received MRI, 10 patients received IVP examination, and 11 received B-ultrasound. Results (1)The very first symptoms usually included back pain, bellyache (10 cases), or urinary tract obstruction (3 cases), with increase of ESR, IgG, CRP value and abnormal renal function.(2)The result of radiological examination showed that 11 lesions of the 14 cases located at retroperitoneum. Ten cases were mass type and 4 cases were diffuse type. Non-contrast CT scanning revealed soft tissue mass at retroperitoneum with inhomogenous or homogenous density. After contrast medium injection the lesions were enhanced with different extent. MRI results showed that the lesions presented low signal in T_1WI, while in T_2WI the signals had no obvious coherence but were different from one case to another. Conclusion Radiological examination is one of the important methods for diagnosis of RPF. Based on the different characteristics of RPF in CT and MRI, together with the clinical findings, we will get valuable references for staging and follow-up of RPF.