Application Of Low Tube Voltage Combined Iterative Reconstruction In CT Examination Of Patients With Cerebral Hemorrhage

Objective 1.To investigate the effect of Sinogram-Affirmed Iterative Reconstruction(SAFIRE)technology on the quality of normal brain CT scan images;2.To explore the clinical application value of low tube voltage combined with SAFIRE technology in CT examination of patients with cerebral hemorrhage.Methods 1.Collect 40 patients(including 14 males and 26 females)who have normal CT scans in our hospital from November 2017 to December 2017.After the normal scan(130kVp FBP reconstruction)is completed,the original data is reconstructed according to SAFIRE 1-5.According to the reconstruction method,it is divided into FBP group,SAFIRE 1 group,SAFIRE 2 group,SAFIRE 3 group,SAFIRE 4 group and SAFIRE 5 group.The average CT value,noise(SD)and Signal-to-Noise Ratio(SNR)of each group are measured,and the image quality of each group was scored to perform correlation statistical analysis.2.Collect 40 patients(22 males and 18 females)who underwent CT scan of our hospital from January to October 2018 due to hypertensive intracerebral hemorrhage.The initial diagnosis was performed with a conventional dose(130kVp FBP reconstruction),and the low-dose(110 kVp FBP reconstruction)scan was performed in the review diagnosis and reconstructed(110 kVp SAFIRE 3 reconstruction).According to the scan tube voltage and reconstruction method,it was divided into normal dose group(130kVp FBP reconstruction),low dose group A(110 kVp FBP reconstruction)and low dose group B(110 kVp SAFIRE 3 reconstruction)to compare subjective score of image quality,SD,SNR,Contrast-Noise Ratio(CNR)and radiation dose.Results1.(1)The subjective scores of the two physicians in the FBP group,the SAFIRE 1 group,the SAFIRE 2 group,the SAFIRE 3 group,the SAFIRE 4 group,and the SAFIRE 5 group were 4.66±0.42 points,4.73±0.37 points,and 4.75±0.39 points,4.90±0.25 points,4.76±0.37 points,and 4.75±0.40 points.The image quality scores of SAFIRE 1-5 were slightly higher than those of FBP group.The difference of image quality score between SAFIRE grade 3 and FBP group was statistically significant(p=0.01<0.05),and it was the highest score and the finest image in 6 groups of images.(2)There was no statistically significant difference in mean CT values between the 6 groups of reconstructed images,but there is a statistical difference between image SD and SNR.Among them,the image SD of SAFIRE 1-5 each group is lower than that of FBP group,and the SNR is higher than that of FBP group.With the increase of SAFIRE level,the image SD is gradually reduced,and SNR is gradually increased.The FBP group has the largest image SD and the smallest image SNR.2.(1)The subjective scores of the two physicians in the conventional dose group(130 kVp FBP reconstruction),low dose group A(110 kVp FBP reconstruction),and low dose group B(110 kVp SAFIRE level 3 reconstruction)were 4.28±0.62 points,4.12±0.58 points and 4.23 ± 0.61 points,respectively.Among them,the conventional dose group had the highest score,followed by the low dose group B,but the low-dose group and the conventional dose group had no statistically significant difference in score results,which could achieve the diagnostic effect.(2)There was no statistically significant ofthe difference in mean CT values among the 3 groups of reconstructed images,but the image SD,SNR and CNR differences were statistically significant.Among them,the low-dose group had a slightly higher image SD than the conventional dose group,and the low-dose group A had the highest SD image.The image SNR and CNR from high to low is followed by low dose group B,conventional dose group,and low dose group A.(3)The conventional dose group CTDIvol,DLP and ED(effective dose)were 61.18 mGy,846mGy.cm,1.95 mSv,respectively,which were higher than the low dose group(CTDIvol=42.61 mGy,DLP=590mGy.cm,ED=1.36mSv).Conclusion1.Compared with the conventional scanning FBP reconstruction algorithm image,SAFIRE technology can reduce image noise,improve image signal-to-noise ratio,and improve image quality.In SAFIRE 1-5,SAFIRE 3 reconstructed image has fineness,sharpness andthe image quality is the best.2.In the CT scan of patients with cerebral hemorrhage,the low tube voltage can significantly reduce the radiation dose of the patient.Combined with the iterative reconstruction(SAFIRE level 3)technology,the image noise can be reduced and the image signal-to-noise ratio can be improved.Image quality meets clinical diagnostic requirements and provides better imaging services for patients with cerebral hemorrhage.