Objective To assess the effectiveness of iterative metal artifact reduction (IMAR) on metal artifacts reduction in thorax scan.Methods Thoracic phantom with two pedicle screws implanted in both sides of the T5 vertebrae was used,with the scan parameters of 130 kV and CARE Dose 4D,the phantom was scanned with and without the screws respectively.Images without screws were reconstructed with FBP.Images with screws were reconstructed with FBP and IMAR respectively.Three ROIs were selected on tissues including aorta,pulmonary and paravertebral soft tissue on image slice adjacent to the screws.The CT value and standard deviations (noise) of ROIs were measured,and the deviation of CT value (△HU) was calculated as the difference between CT values in images with and without screws.Twenty-six cases who received chest CT examination and with pedicle screw implant in scanning range were collected.The scanning parameters and image reconstruction methods were the same as phantom scan.The CT value (HU) of metal artifacts adjacent to vertebrae and dorsal soft tissue was measured,and the image quality of reconstructed image by two skilled radiologists independently was evaluated.Results In the phantom after implanted screws,the noise were significantly reduced by IMAR compared to FBP in all the three ROIs of aorta,pulmonary and paravertebral soft tissue (P＜0.05),and the △HU was significantly smaller in IMAR compared to that with FBP (P＜0.01).In 26 patients,there were significant differences in CT value of vertebral bone tissue and dorsal soft tissue between FBP and IMAR (P＜0.05),and the subjective evaluation scores of the two image reconstruction methods showed a statistically significant difference (P＜0.05).Conclusion IMAR can significantly reduce streak artifacts of metal implant and adjuste the CT values of artifact affected tissues to make it more close to the true value without metal implant.

Neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) is an autosomal recessive disease caused by SLC25A13 gene mutations, and is characterized by delayed jaundice clearance, liver dysfunction, and elevated aminoacidemia. The confirmed diagnosis depends on gene analysis. Citrin deficiency is one of the important causes of neonatal intrahepatic cholestasis in China. Recently more and more researches about NICCD were reported. The paper summarized the epidemiology, pathogenesis, clinical characteristics, and progresses in diagnosis and treatment of NICCD.

This study aims to evaluate the ability of C-arm cone-beam CT to detect intracranial hematomas in canine models. Twenty one healthy canines were divided into seven groups and each group had three animals. Autologous blood and contrast agent (3 mL) were slowly injected into the left/right frontal lobes of each animal. Canines in the first group, the control group, were only injected with autologous blood without contrast agent. Each animal in all the 7 groups was scanned with C-arm cone-beam CT and multislice computed tomography (MSCT) after 5 minutes. The attenuation values and their standard deviations of the hematoma and uniformed brain tissues were measured to calculate the image noise, signal to noise ratio (SNR) and contrast to noise ratio (CNR). A scale with scores 1-3 was used to rate the quality of the reconstructed image of different hematoma as a subjective evaluation, and all the experimental data were processed with statistical treatment. The results revealed that when the density of hematoma was less than 65 HU, hematomata were not very clear on C-arm CT images, and when the density of hematoma was more than 65 HU, hematomata showed clearly on both C-arm CT and MSCT images and the scores of them were close. The coherence between the two physicians was very reliable. The same results were obtained with C-arm cone-beam CT and MSCT grades in measuring SD value, SNR, and CNR. The reasonable choice of density detection range of intracranial hematoma with C-arm cone-beam CT could be effectively applied to monitoring the intracranial hemorrhage during interventional diagnosis and treatment.
Animals ; Cone-Beam Computed Tomography ; Disease Models, Animal ; Dogs ; Hematoma ; diagnosis ; Image Processing, Computer-Assisted ; Intracranial Hemorrhages ; diagnosis ; Multidetector Computed Tomography ; Signal-To-Noise Ratio

Objective To compare the differences of pulmonary nodule detection rates between iterative reconstruction (sinogram affirmed iterative reconstruction,SAFIRE)algorithm and filtered back projection (FBP) algorithm in chest CT, and to evaluate the detection accuracy.Methods Three groups of tube voltage values of 80,100,and 120 kV were defaulted on the new dual-source CT,with automatic mAs care dose 4D technology, the chest phantom with simulated pulmonary nodules was scanned, then the images were reconstructed with FBP and SAFIRE (grade 1-5 ),respectively. The detection rates of simulated pulmonary nodules in the chest CT images reconstructed of SAFIRE (grade 1-5 )and FBP were compared, and their diameters and CT values were measured.Results With the same tube voltage, no significant difference was found in the detection rate of simulated pulmonary nodules between SAFIRE (grade 1-5 )and FBP (P>0.05 ), the diameter deviation of simulated nodules of SAFIRE (grade 3 )was less than FBP, and the difference in the average CT value of the simulated nodules between SAFIRE (grade 3)and FBP was not statistically significant (P>0.05);the simulated nodule detection rate of 100 kV was equivalent to the detection rate of 120 kV,the simulated nodule (-800 HU and 3 mm )detection rate of 80 kV was less than that of 120 kV;as the tube voltage reduced,or simulated nodule diameter decreased,or the density of simulated nodule reduced,the nodule’s diameter deviation was increased. Conclusion Compared with FBP,the capabilities of SAFIRE in pulmonary nodule detection in different densities and different sizes are same,and SAFIRE algorithm is helpful for accurate displaying of pulmonary nodules,and it can be used for low-dose CT lung cancer screening program.

Objective To evaluate the accuracy and efficiency of the Monte Carlo software in measuring the radiation dose to the patients who received the CCTA (Coronary Computed Tomography Angiography) examination.Methods A anthropomorphic chest phantom underwent CCTA using three scan parameters (tube voltage 80 kV,100 kV and 120 kV).Computer Software ImpactDose 2.0 was used to compute the chest organ dose on the basis of the three groups tube voltage CT scan characteristic,and the stimulation results of ImpactDose 2.0 software was verified by use of anthropomorphic phantom thermoluminescence dosimeter experiment method.Results For all the measured organs except for lung,the absorbed organ dose and effective dose of three groups of tube voltages of CCTA measured by the InpactDose 2.0 was lower than those as measured by anthropomorphic phantom study.The relative error of both methods was within ± 50％.Conclusions Monte Carlo software can be used to estimate the levels of radiation dose during CCTA examination with a tolerable error within the acceptable range.

Objective To study the influence of various doses and injection rates of contrast agent on CT perfusion in rabbits' liver with a deconvolution mathematical model. Methods Eight rabbits were enrolled in the experiment. Randomized block design was adopted. The treatment factor (contrast medium injection rate) was classified into 0.5, 1.0, 1.5 ml/s, while the subjects were divided into 3 blocks with contrast medium injection dose of 0.5, 1.0 and 1.5 ml/kg. The data obtained at CT perfusion imaging were then transferred to the workstation. Absolute values of 7 perfusion parameters (hepatic arterior fraction, blood flow, blood volume, permeability surface, mean transmit time, hepatic artery perfusion and portal vein perfusion) were measured with perfusion software (Perfusion 3). Results The dose of contrast medium had significant effect on peak enhancement of the aorta, the portal vein and liver tissue (P<0.05), whereas the injection rates had significant influence on the arrival time to peak enhancement of the aorta and the portal vein. However, the dose of contrast medium and injection rates had no significant effect on perfusion parameters (P>0.05). Conclusion CT perfusion imaging with a deconvolution mathematical model can quantify the hemodynamic functional status in liver with stable results. This technique does not need strict confinement to dose and injection rate of contrast medium, and has great potential value to be put into clinical use.

Objective To investigate the influence of acquisition time of C-arm cone-beam CT on image quality and radiation dose of cerebral angiography.Methods C-arm cone-beam CT of cerebral angiography was performed on the male anthropomorphic head phantom,with DynaCT imaging mode and the acquisition time of 5 s,8 s and 20 s were used.Scanning was performed with each acquisition time for three times,and VR,MIP and MPR images were reconstructed.The attenuation values and their standard deviations of intracranial segment of the internal carotid artery (ICA),middle cerebral artery(MCA),anterior cerebral artery(ACA) and uniformed brain tissues were measured to calculate the image noise,signal to noise ratio (SNR) and contrast to noise ratio (CNR).We used the image noise,SNR and CNR as the objective standard to evaluate the image quality,and One-way ANOVA analysis of variance was used to assess the difference among them.A scale with scores 1 to 5 was used to rate the quality of the reconstructed image of ICA,MCA,ACA as a subjective evaluation,the difference among the evaluation scores were analyzed using Kruskal-wallis.We recorded the dose area product (DAP) of each acquisition time and the effective dose(ED) was calculated to assess the radiation dose,the difference among them were analyzed using One-way ANOVA analysis of variance.Results In C-arm cone beam CT 20 s imaging,the SNR of intracranial segment of the ICA,M CA,ACA were 22.29± 1.41,29.36 ±0.11 and 23.13 ±2.10 respectively,in 5 s imaging13.83 ±0.61,14.65 ±0.16 and 12.79±0.19 respectively,in 8 s imaging 14.92±0.96,18.97 ± 1.24 and 16.65 ±0.46 respectively,all the results showed a significant difference (F valued 58.19,327.29,52.74 respectively,all P valued＜0.01),the CNR of 20 s imaging were higher than that of 5 s and 8 s imaging,the Noise of ICA,MCA,ACA and the uniformed brain tissues of 20 s imaging were lower than that of 5 s and 8 s imaging,all the results showed significant difference (all P valued＜0.01).The subjective evaluation scores of VR imaging of 5 s,8 s and 20 s were 3.61 ±0.49,4.06±0.53,4.72±0.45 respectively,the scores of MIP imaging were 3.42±0.50,3.83±0.65 and 4.50±0.51 respectively,the scores of MPR imaging were 2.83±0.45,3.14±0.35 and 3.67±0.49 respectively,all the results showed significant difference (x2 valued 51.29,42.25 and 43.56 respectively,all P valued ＜0.01).The DAP values in C-arm cone beam CT 5 s,8 s and 20 s imaging were (9.11 ±0.18),(13.81±0.75)and(58.62±0.62)Gy· cm2,ED values were (0.91 ±0.02),(1.38±0.75)and(5.84± 0.11) mSv,all the results showed significant difference (F valued 3 720.30 and 3 654.85 respectively,all P valued＜0.01).Conclusion The image quality and radiation dose of C-arm cone-beam computed tomography are closely correlated with acquisition time.

To assure the effective operation of certification and accreditation in the laboratory management system, further strengthen the instruments and equipment management, and provide specific recommendations on improvement of internal audit, management review and continuous improvement of management system. The inspector program had been firstly established and complemented. Through the inspection, we identified many deficiencies, made many specific recommendations for improvement. After inspection, the working procedures were improved;data from department were more rigorous, scientific and just;hardware foundation was established for international mutual recognition.

The prevalence of stroke is increasing in China and the world,and cognitive impairment,as one of the most common complications of stroke,has attracted much attention of many researchers.Post-stroke cognitive impairment (PSCI) has severely affected patients' daily living ability,which has brought heavy burden to family and society.In addition,with the increasing of age,PSCI may even develop into dementia,so we need to give early diagnosis,early treatment and prevention to patients with PSCI.In this paper,the concept of PSCI,neuropsychological characteristics,screening scale and treatment are described to improve the staff awareness and management of PSCI.

Objective To investigate the inhibitory effect and molecular mechanism of Huaier granule on the growth of sorafenib resistant hepatocellular carcinoma(HCC)cells.Methods The gradient concentration of Huaier granule was used to treat HCC cells,and the effect of Huaier granule on the proliferation,migration and invasion of sorafenib resistant HCC cells was analyzed.Bioinformat-ics methods were used to analyze the possible interaction between microRNA-31-5p(miR-31-5p)and sprouty-related proteins with an EVH1 domain 1(SPRED1).The expression levels of miR-31-5p and SPRED1 in HCC cells were detected by real time fluorescence quantitative polymerase chain reaction(qRT-PCR);cell viability,proliferation,migration,invasion and apoptosis were detected by CCK-8,colony formation,scratch healing,Transwell and flow cytometry;RNA immunoprecipitation(RIP)as-say and dual luciferase assay were used to verify the binding relationship between miR-31-5p and SPRED1.Results Huaier granule could significantly inhibit the proliferation,migration and invasion of sorafenib resistant HCC cells,and induce apoptosis.Bioinformatics analysis showed that miR-31-5p was highly expressed in HCC,and Huaier granule was able to down-regulate the expression of miR-31-5p,inhibit the proliferation and metastasis of sorafenib resistant HCC cells,and induce apoptosis;miR-31-5p showed a targeted inhibition effect on the expression of SPRED1.SPRED1 was down-regulated in HCC,and overexpression of SPRED1 was able to reverse the promoting effect of overexpression of miR-31-5p on proliferation and metastasis of sorafenib resistant HCC.Conclusion Huaier granule can inhibit sorafenib resistant HCC metastasis through the miR-31-5p/SPRED1 axis,indicating that Huaier granule has the potential to be used as a novel drug for HCC treatment.