Objective To explore the clinical application of material decomposition technique on spectral CT imaging and evaluate hemodynamic changes in different liver lobes with liver cirrhosis.Methods 30 patients with liver cirrhosis diagnosed clinically in our hospital were collected and underwent enhanced scanning of abdomen with spectral CT protocol.The monochromatic energy images and iodine-based material decomposition (MD) images were reconstructed after scanning.The iodine concentration (IC) was measured in five liver lobes (the caudate, left lateral, left inner, right anterior and right posterior lobes) and the abdominal aorta of the same axial slice in both the arterial phase (AP) and portal venous phase (VP) on the iodine-water based material decomposition images.The arterial iodine fraction (AIF) and the portal venous iodine concentration (PVIC) as well as the normalized iodine concentration (NIC) during the AP and VP were calculated.The differences of IC,the NIC,the AIF,and the PVIC in five liver lobes in AP and VP were compared by using single factor analysis of variance.Results The IC,the NIC in both AP and VP and the AIF of the caudate liver lobe were higher than those of other four liver lobes, with statistically significant difference (P<0.05), while these values in the other four lobes showed no statistically significant difference (P>0.05).The PVIC of the caudate liver lobe was slightly lower than that of the other four liver lobes, however, the difference was not statistically significant (P=0.929).Conclusion The quantitative iodine concentration measurement of liver lobes on spectral CT material decomposition technique can evaluate the hemodynamic changes in liver lobes with liver cirrhosis,and provide more information about the change of blood flow in liver cirrhosis.

As a safe,cheap and effective diabetes drug,metformin has been used for many years.Diabetes increases the risk of liver cancer and affects its prognosis.In recent years,it is found that metformin reduces the pancreatic cancer risk in the treatment of diabetic patients,a large of experiments also prove that it has anti-cancer and synergistic anticancer effect.This paper focused on the effects of metformin on treatment of Ⅱ type diabetes,discussed the curative effect on liver cancer,suggested the molecular biology mechanism of inhibiting tumor,listed the latest experiment researches,analyzed the existed clinical data,proposed the further study of anticancer mechanism and clinical treatment.Metformin for a future role in prevention of hepatocellular carcinoma in patients with type Ⅱ diabetes are briefly summarized and future prospects,which in type Ⅱ diabetic patients with liver cancer in a prospective study of the effect of treatment.Mefformin for application in other cancer prevention also raises possibilities.

PurposeTo explore the feasibility of personalized energy spectrum scanning in upper abdomen CT by comparing the image quality and radiation dose of optimizing choice spectrum scanning protocol with conventional 120 kVp scan.Material and Methods Sixty patients undergoing abdominal CT scan with and without contrast enhancement were prospectively collected and randomly assigned into two groups. Group A (30 patients) underwent conventional 120 kVp scan and spectral enhancement scanning; group B (30 patients) underwent spectrum scan and 120 kVp enhancement scanning. Spectral scanning protocol was based on individual choice with conventional 120 kVp NI10-5 mm average mAs scan for every patient. The CT dose index of volume (CTDIvol) and effective dose (ED) during non-contrast phase and portal venous phase were recorded. The CT value, standard deviation (SD), signal noise ratio (SNR) and contrast noise ratio (CNR) were measured in the liver parenchyma, spleen parenchyma and portal venous trunk.Results The CTDIvol and ED of spectrum scanning were less than 120 kVp scan but there was no statistical difference (P>0.05). The SD of group B GSI imaging was less than group A 120 kVp (P<0.05), while the SNR was greater than group A. The SD of group A GSI portal venous phase in the liver, spleen and portal vein was less than group B 120 kVp (P<0.05).ConclusionThe optimized energy spectrum scanning protocol can reduce radiation dose with quality of single energy image from the energy spectrum equal to or better than the conventional 120 kVp scanning protocol. Personalized energy spectrum scan protocol provides multi-parameter diagnosis and multi-application platform and can be used routinely in the upper abdomen scan.

Purpose To explore the value of spectral coronary CT angiography (CCTA) in reducing radiation dose and contrast dose using individualized optimal monochromatic imaging.Materials and Methods Sixty patients with suspected coronary disease were recruited in the study,who were randomly divided into two groups:group A (n=30) using conventional CT protocol with 350 mgI/ml contrast agent;group B (n=30) using low dose spectral CT imaging mode with 300 mgI/ml contrast agent.The images of group A were reconstructed with conventional process,and the images of group B were reconstructed with Optimal CNR to obtain the optimal monochromatic energy images.The images of both groups were transferred to an Advanced Workstation for analysis.Double-blinded method was carried out to qualify the images.CT values of coronary artery segments,as well as standard deviations (SD),the signal-to-noise ratio (SNR),contrast-to-noise ratio (CNR) of aortic sinus were measured.Radiation doses and iodine intake were compared between the two groups.The optimal keV distribution in group B was analyzed.Results There was no significant difference for the subjective scoring of image quality,CT value of each coronary artery segment,SD,SNR,and CNR values between the two groups (P＞0.05).The effective radiation dose and total iodine load in group B were less than that in group A (P＜0.05).The optimal energy distribution for group B was 60-75 keV,average at (66.50+3.91) keV.Conclusion Compared with the conventional CT protocol,spectral CT imaging at optimal energy levels combined with iterative reconstruction can effectively reduce the radiation dose and iodine load,and obtain better images than usual protocol.

Objective To explore the application of low dose of radiation combined with low concentration of contrast medium in the energy spectrum CT of the coronary artery angiography.Methods 60 patients with suspected diagnosis of coronary heart disease were randomly divided into A,B two groups,30 cases in each group.Group A with 350 mg I/mL contrast agent,undergoing conventional CT scanning;Group B using 300 mg I/mL contrast agent,the gems energy spectrum CT scanning with low-dose.Two groups both adopted forward-looking heart switch control scanning mode.After scanning,group A reconstructed conventional images of 40% ASiR sequence,group B rebuilded axial surface images of single energy 65 keV and 40% ASiR sequence,all the reconstruction images were introduced to AW4.6 workstations used for analysis.Double-blind subjective rating was done by two experienced doctors to measure CT values and SD of aortic sinus (AS),left main (LMA),the left anterior descending branch proximal (LAD-p),left circumflex branch proximal (LCX-p), right coronary artery proximal (RCA-p)and pericardial fat,AS the noise (SD),to calculate the signal-to-noise ratio (SNR)and contrast to noise ratio (CNR),to calculate the effective doses of radiation(ED)by recording CTDI and DLP,and to record iodine intake.By using two independent samples t test to compare two groups of patients’the effective radiation doses,iodine intake,the average CT value,SD,SNR and CNR.Results The subjective image quality score differences and coronary measuring section CT values between the two groups had no statistical significance.In the aspects of effective radiation dose,group B reduced about 29% compared to group A,the difference was statistically significant.Iodine intake in group B decreased about 16% than in group A.Conclusion In coronary artery CT imaging, spectral scanning with low dose of radiation and reconstruction images with single energy can effectively reduce the radiation dose and iodine intake,at the same time it can obtain the approximate image quality like conventional scanning.

Objective To explore the clinical value of adaptive statistical iterative reconstruction(ASIR)combined with automatic tube current modulation in low dose scan of chest CT.Methods 80 patients who underwent chest CT scan were randomly divided into four groups,with a noise index(NI)of 14,16,18,and 20,respectively.Automatic tube current modulation technique for chest CT scan was adopted for all patients.The standard dose group,with a NI of 14,was reconstructed with FBP.While the low-dose groups,with a NI of 16,18 and 20,were reconstructed with four ASIR levels(20% ASIR,40% ASIR,60% ASIR and 80% ASIR) in each group.The volume CT dose index(CTDIvol),dose length product(DLP)and effective dose(ED)were recorded of the four groups.The signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were calculated of the different reconstruction groups. Two radiologists with more than five years of work experience blindly scored the subjective image quality.Results Effective dose of the four groups with different NI were(3.29 ± 1.21)mSv,(3.10 ± 1.07)mSv,(2.20 ± 0.82)mSv and(1.97 ± 1.21)mSv,respectively. In all the reconstruction groups,when NI was constant,the greater the ASIR,the lower the SD.When ASIR percentage was constant, the SD was increased and the SNR was reduced along with NI rising up.When the parameters were set as NI 18 and ASIR 60%,the SD would be smaller and SNR would be higher than that of a standard dose group.In aspect of the scores from subjective image quality evaluation,there was no significant difference(P> 0.05).The average ED was decreased by about 33.2% when compared to the standard dose group.Conclusion Combining automatic tube current modulation with ASIR has a certain clinical practicality.When the NI is set at 18 and ASIR is 60%,the image quality can be optimal for not only satisfying the requirements of clinical diagnosis, but also reducing radiation dose in chest CT scanning.

Objective To explore the effect of deep learning image reconstruction(DLIR)algorithm combined with"double low"[low voltage(kV)and low contrast agent dosage]technique on the image quality of coronary computed tomography angiography(CCTA)in overweight patients compared with adaptive statistical iterative reconstruction(ASIR-V)and filtered back projection(FBP).Methods Fifty-two patients with body mass index(BMI)between 25.1 kg/m2and 28 kg/m2 who underwent CCTA scanning were prospectively selected,all of whom scanned on a GE Revolution APEX-CT with a tube voltage of 80 kV,a smart mA(500-1 300 mA),a noise index of 30,and a contrast dosage of 0.5 mL/kg;four groups of images were reconstructed for each patient,FBP,50％ASIR-V,DLIR-M,and DLIR-H.The CT and SD values of the aorta(AO)root,the proximal segment of the right coronary artery(RCA),the left circumflex(LCX),the left anterior descending branch(LAD)and the pericardial fat were measured,and the signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were calculated.Two doctors experienced in the diagnosis of cardiovascular disease were selected to subjectively score the reconstructed images using a double-blind method.The SD value,SNR value,CNR value and subjective scores of images in the four groups were compared.Results In the objective image quality evaluation,there were statistically significant differences in SD value,SNR value and CNR value of reconstructed images in the four groups(P＜0.05).As the four groups of reconstruction algorithms FBP,50％ASIR-V,DLIR-M,and DLIR-H were changed sequentially,the image SD value gradually decreased,the SNR value and CNR value gradually increased,and the DLIR-H group had the lowest SD value and the highest SNR and CNR values.In the subjective image quality evaluation,the subjective scores of the two doctors had good consistency(Kappa value=0.900),and the difference between them was statistically significant(P＜0.001).The subjective scores of DLIR-M and DLIR-H groups were higher.Conclusion DLIR algorithm combined with"double-low"technique can significantly improve the CCTA image quality of overweight patients,which is better than 50％ASIR-V and FBP.

Objective To explore the application value of deep learning image reconstruction(DLIR)with coronary computed tomography angiography(CCTA)using 100 kV.Methods Sixty patients who underwent CCTA were selected.The tube voltage of 100 kV,noise index of 24 were applied.The 60％adaptive statistical iterative reconstruction-Veo(ASIR-V)and DLIR-low(DLIR-L),DLIR-medium(DLIR-M)and DLIR-high(DL1R-H)were reconstructed.The CT values and standard deviation(SD)values of the aortic root,left main artery,left anterior descending artery,left circumflex artery,right coronary artery and pericardial fat of the four groups of images were measured,and the signal-to-noise ratio(SNR)and contrast-to-noise ratio(CNR)were calculated.Two radiologists with five-year working experience subjectively evaluated the image quality using a five-point method double-blindly.Results The differences in noise(SD values),SNR values and CNR values among the four groups of images were statistically significant(P＜0.001).As the reconstruction gradually changed of 60％ASIR-V,DLIR-L,DLIR-M and DLIR-H,the coronary SD values gradually decreased,while the SNR values and CNR values gradually increased,among which the DLIR-H had the lowest SD values and the highest SNR values and CNR values.The subjective scores of the four groups of images by two radiologists showed good consistency(Kappa value=0.929,P＜0.001),and the subjective scores were all above 3 points which met the clinical diagnosis criteria.The subjective scores of DLIR-L,DLIR-M and DLIR-H were significantly higher than those of 60％ASIR-V(P＜0.001),with the DLIR-H achieving the highest subjective score.Conclusion DLIR can significantly reduce image SD value and improve image quality of CCTA with 100 kV,among which DLIR-H has the best effect on improving CCTA image quality.