Objective To explore the optimized scanning parameters of low-dose un-enhanced chest CT with sinogram affirmed iterative reconstruction (SAFIRE).Methods Eleven healthy adult domestic dogs underwent chest scanning of 120 kV,100 kV,80 kV,70 kV with a fixed tube current of 65 mA and halved tube current of 32 mA with a fixed tube voltage of 100 kV.The data were reconstructed with filtered back projection (FBP)and SAFIRE (strength grade 3)respectively to obtain ten groups of images.The regular dose (120 kV/65 mA ) combining with FBP reconstruction was as normal control group,and other groups as experimental groups.CT dose index (CTDI), dose length product (DLP),and effective dose (ED)at different dose were compared,and average CT value,noise,signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR)and image quality score of ten groups of images were comparatively analyzed.Results No significant differences were found in average CT value for lung tissue,the superior vena cava,the aortic arch,and spinal muscles among ten groups (P >0.05),except adipose tissue (P <0.05).Compared to the control group,radiation dose of the 100 kV/65 mA-SAFIRE group decreased by 40.00%,noise of this group reduced,SNR and CNR increased,image quality score was slightly higher.Radiation dose of 80 kV/65 mA and 100 kV/32 mA groups,compared to the control group,decreased by 71.33% and 70.00% respectively ;image quality was slightly degraded but the subjective image quality scores were above 4 ,which on the latter group was slightly higher than that on the former.Image quality of 70 kV/65 mA group was reduced but could meet the requirements of diagnosis (image quality score >3),and the radiation dose of this group decreased by 81.33%.Conclusion Reconstructed with SAFRIE technology,the image quality of 100 kV/65 mA scanning of chest CT is similar to that of routinely reconstructed images in regular dose,while the image quality of 70 kV/65 mA scanning can not only meet the requirements of diagnosis but also obviously reduce radiation dose.

Objective To investigate the value of low kilovoltage (100 kVp)in combination with sinogram affirmed iterative re-construction (SAFIRE)of flash dual source CT in pelvic scan in comparison with routine kilovoltage (120 kVp)and filtered back projection (FBP).Methods 88 patients with suspected pelvic lesions underwent CT scan,and the range of BMI was 1 9 kg/m2

Objective To study the value of SAFIRE reconstruction technique in the liver plain CT scan by the comparison of dis-plays to the liver separately by SAFIRE and traditional FBP reconstructions after DSCT scan.Methods 48 patients clinically doub-ted to have hepatic lesions were scanned by DSCT in liver,then the average CT value,noise,signal to noise ratio (SNR),contrast to noise ratio (CNR)and subjective scoring on image quality were compared after FBP and SAFIRE 1-5 reconstructions.Results There was no statistical difference on the average CT value of liver parenchyma in all 6 groups (P >0.05).The differences were sta-tistically significant (P <0.05)on noise,SNR,CNR and subjective scoring.SAFIRE 5 reconstruction had the least noise and the largest SNR and CNR.For the images of SAFIRE 1 and SAFIRE 5,the image subjective scoring was lower than that by FBP;for the images of SAFIRE 2-4,the image subjective scoring is higher than that by FBP;and SAFIRE 3 had the highest score.But for the rate of lesion detection,all the images were the same.Conclusion SAFIRE reconstruction strength 3 could produce the idealest image quality.SAFIRE reconstruction can decrease noise and improve SNR and CNR,and have a potential effect on decreasing the scan dose.

PurposeTo analyze the urinary stone chemical composition using dual source CT (DSCT) dual energy imaging.Materials and MethodsNinety-seven stone samples with known chemical composition were placed in fresh swine kidneys and examined with DSCT dual energy scan, including 55 calcium oxalate stones, 13 hydroxyapatite stones, 9 uric acid stones, 4 cystine stones, 2 struvite stones and 14 mixed stones. The mean attenuation values and dual energy index (DEI) were measured at 80 kV and 140 kV. The stone composition was analyzed to determine the sensitivity, specificity and accuracy.ResultsDual energy analysis showed 59 calcium oxalate stones, 11 hydroxyapatite stones, 9 uric acid stones, 4 cystine stones and 14 mixed stones. 2 hydroxyapatite stones were erroneously marked as calcium oxalate stones and 2 struvite stones as calcium oxalate stones. The accuracy was 95.88% (93/97). The difference CT value at 80 kV and 140 kV and DEI value were statistically significant (P<0.05). The sensitivity for detecting calcium oxalate stones, hydroxyapatite stones, uric acid stones and cysteine stones were 100.00%, 84.60%, 100.00% and 100.00%, respectively; with specificity of 85.70%, 100.00%, 100.00% and 100.00%, respectively; and the accuracy were 95.18%, 97.59%, 100.00% and 100.00%, respectively.ConclusionDSCT dual energy imaging accurately analyzes the chemical composition of urinary stone in vitro, which provides important clinical value in analyzing the urinary stonesin vivo.

Objective To investigate the value of low tube voltage with sinogram affirmed iterative reconstruction (SAFIRE) through comparing the image quality of regular dose scanning with filtered back projection (FBP) reconstruction and low-dose scanning with SAFIRE. Methods Eleven healthy adult domestic dogs were scanned with different doses. The regular dose of 120 kV/65 mA in combination with FBP reconstruction was set as the normal control group, and 100 kV/65 mA plus SAFIRE reconstruction was used as the low kV group. The CT dose index (CTDI), dose length product (DLP), and the effective dose (ED) at different doses were compared, and the average CT value, noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and the image quality score of two groups of images were also analyzed. Results ED in the low kV groups was reduced by 39.33%compared to that in the normal control group. No significant differences were found in the average CT value of the same tissue among these two groups (P > 0.05). Compared with the normal control group, image noise of the lung tissue, superior vena cava and spinal muscle of low kV group were consistently decreased, SNR was in also creased, while the noise ratio contrast between superior vena cava and fat was increased. The image quality score of the low kV group was increased by 1.70%compared to that of the normal control group. Conclusion The low kV scan with SAFIRE technology can decrease the radiation dose and improve image quality in chest CT examination of domestic dogs, with a potential value in the clinical promotion and the application.

Objective To evaluate the value of the SAFIRE reconstruction technique for the nasal traumatic lesions .Methods Six‐ty‐seven patients with nasal traumas were scanned by the orbital scan and were reconstructed with FBP and SAFIRE (strength grade 1 to 5) respectively .Then a comparative analysis for six kinds of reconstructed images were conducted on the average CT value ,noise ,signal to noise ratio (SNR) ,contrast to noise ratio (CNR) ,subjective scoring and lesion detection .Results Compared with reconstruction by FBP , SAFIRE (strength grade 1 to 5)reconstruction ,for the noise ,decreased to 20 .4% ,31 .4% ,39 .7% ,46 .5% and 57 .2% respectively ;For the SNR ,increased to 33 .3% ,54 .7% ,75 .4% ,87 .4% and 101 .4% respectively ;For the CNR ,it also increased to 23 .0% ,36 .4% ,57 .7% , 87 .4% and 106 .5% respectively ;The difference was statistically significant (P< 0 .05) .For the images of SAFIRE‐1 and SAFIRE‐5 ,the image subjective scoring was lower than that by FBP ;for the images of SAFIRE‐2 and SAFIRE‐4 ,the image subjective scoring was higher than that by FBP ;and SAFIRE‐3 had the highest score .But for the rate of lesion detection ,all the images were the same .Conclusion CT scan combined SAFIRE reconstruction technique can decrease effectively the noise and increase the image quality in the traumatic nasal scan , as well as has a potential effect to decrease the scan dose .

OBJECTIVE:To explore the protective effect of L-ornithine-L-aspartate on ischemia-reperfusion injury after partial hepatectomy. METHODS:104 patients underwent partial hepatectomy(vessel occlusion in portal fissure)were randomly divided in-to control group(53 cases)and trial group(51 cases). Control group was given routine liver-protective drugs,and trial group was additionally given L-ornithine-L-aspartate 10 g added into 5%Glucose injection 250 ml intravenously before surgery,for 7 consecu-tive days. The fasting peripheral venous blood was collected in 2 groups on first day before surgery and first,forth and sixth day af-ter surgery to detect liver function;the changes of main aminopherase index(ALT and AST)were compared between 2 groups at different portal fissure vessel occlusion time after surgery. RESULTS:There was no statistical significance in the difference of liver resection range,blood loss,first porta hepatis vessel occlusion time and anesthesia time in both groups during operation (P>0.05). Compared to before surgery,liver function indexes raised to different extent in 2 groups after surgery,with statistical signifi-cance(P<0.05). The levels of AST and ALT in trial group were significantly lower than in control group on first,forth and sixth day after surgery,while albumin level was significantly higher than control group,with statistical significance(P<0.05). Total bili-rubin levels of both groups were approximate basically,there was no statistical significance(P>0.05). Among those patients under-went porta hepatis vessel occlusion with Pringle method and with occlude occlusion time ≥15 min,the AST and ALT level of con-trol group was higher than those of trial group after surgery,but albumin level was below trial group,with statistical significance (P<0.05). CONCLUSIONS:L-ornithine-L-aspartate could improve liver function fast and effectively for partial hepatectomy pa-tients,especially for the patients underwent porta hepatic vessel occlusion with Pringle method for a long time(obvious ischemia-re-perfusion injury).

Objective To investigate the performance of dual source CT scanning combined with low-tube-voltage iterative reconstruction (SAFIRE) for demonstrating coronary artery calcium plaques. Methods 70 patients with clinically suspected coronary atherosclerosis and with normal BMI received SAFIRE-3 or filtered back projection (FBP) for reconstruction after undergoing CT scans with tube voltage range of 100 kV. The CT images (average CT values, noise, SNR, and CNR) and subjective scores (number of calcium plaque, calcium plaque adjacent artifacts, and image quality) were compared between the two groups. Results The average CT value of the aortic root did not differ significantly between the two procedures for reconstruction (P > 0.05). Ob jective evaluation of the images (noise, SNR, and CNR) between the two groups was statistically significant (P < 0.05 for all comparisons), so was image subjective rating (number of calcium plaque and rate of calcium plaque edge)(P < 0.05 for all comparisons). SAFIRE-3 reconstruction was markedly superior to FBP reconstruc-tion. Conclusions Low kilovoltage combined with reconstruction of SAFIRE-3 can reduce calcium plaque adja-cent artifacts and enhance quality of images , which is better than FBP in displaying the morphology and adjacent conditions of calcified plaque; therefore it is worth popularizing.

Objective Based on the teeth in vitro skull specimen to investigate the feasibility and accuracy of CARE kV CT scan for reducing radiation dose. Methods Of eight fixed and preserved skull teeth were scanned repeatedly in groups of A, B, C. In expose factors of 100 kVp/150 mAs in conventional scanning of group A, open CARE Dose 4D scan of group B and CARE kV scan of group C. We assessed the radiation dose in the group A, B and C, the average CT values of the images, noise, SNR, CNR and subjective ratings. Results Three groups of actual scan tube current, tube voltage and radiation dose were statistically significant (P < 0.05). Compared with group A, the radiation dose in the group B was reduced by about 13.76% and 26.61%reduced in the C group. The average CT values of the images and the noise SNR, CNR and subjective ratings hasd no significant difference (P > 0.05). Conclusion CARE kV technology based on the use specimens tooth can reduce the radiation dose, protect image quality, and be consistent to the reports of previous researches.

Objective To investigate the feasibility of chest examination using ultra-large pitch Turbo Flash in Force CT in preschool children without sedative.Methods A total of 90 preschool children evaluated as nervous or frightened were equally divided into 3 groups according to the scanning time.For group A,the routine scan with the mode of CARE Dose 4D/CARE kV was performed,and the sedative was used.For group B,the scan with ultra-large pitch Turbo Flash model and pitch as 3.0 was performed,and the sedative was used.For group C,the same scan mode as group B was performed but without sedative.The scanning time,radiation dose,image quality and the diagnostic efficiency were compared among 3 groups.Results There were no significant differences of the CT values of the aorta root,spinal posterior muscles and subcutaneous fat,the noise of the aorta root,SNR and CNR among 3 groups (all P＞0.05).Moreover,no significant differences of the subjective score of image quality in pulmonary window and mediastinum window images were found among 3 groups (both P＞0.05).The scanning time and radiation dose indexes (CT dose index volume [CTDIvo1],doselength product [DLP],effective dose [ED]) of group A were significantly higher than those of group B and group C (all P ＜0.05),while there were no significant differences between group B and group C (all P＞0.05).There were no significant differences between the CT diagnosis and clinical diagnosis results in all 3 groups (all P＞0.05).Conclusion It can shorten the scanning time and decrease the radiation dose by using the mode of ultra-large pitch Turbo Flash.And the satisfactory image quality can be obtained without sedative for nervous or frightened preschool children.