The Clinical Application Of Temporal Bone Low-dose Scanning And Inner Ear Bony Structure Measurement Of Mild Sensorineural Hearing Loss With Dual-Source CT

The clinical application of temporal bone low-dose scanning with Dual-Source CTObjective(1) One case adult head specimen in FLASH CT on different tube voltage,tube current, open CARE DOSE4Dand CARE kV scanning technology, adopting SAFIRE(3) and FBP reconstruction technique. The scores of imaging quality and radiation dose were evaluated by two reviewers.which discuss FLASH CT the feasibility of using different technology of temporal bone low-dose scan and its clinical value.(2)To explore the value of using intelligent optimal kV scanning technology (CARE kV) with FLASH CT temoral bone in reducing the radiation dose and its effect on image quality.(3) To investigate the effects of Sinogram Affirmed Iterative Reconstruction (SAFIRE) on application value in Flash CT temporal bone high resolution scan and compare with regular filtered back projection (FBP).(4) To evaluate radiation dose and image quality of FLASH CT for the temporal bone high resolution scan with CARE kV technology、Safire reconstruction technique and low kV.Materials and Methods(1) Preliminary experiments using one case specimen, underwent temporal bone HRCT with CARE DOSE4D,CARE kV,FBP and Safire (3) reconstruction technique; Using various tube voltage(120kV,100kV,80kV,70kV), tube current(180mAs、120mAs、60mAs、50mAs、40mAs、30mAs) temporal bone high resolution scan.compared the image noise and radiation dose.(2)60patients underwent temporal bone HRCT scanning were randomly divided into two groups. GroupA(30patients) underwent temporal bone HRCT with CARE Dose4D and SAFIRE(3) reconstruction technique, groupB(30patients) with CARE Dose4D and CARE kV and SAFIRE(3) reconstruction techniques. The imaging quality (mean CT value, noise, SNR, CNR, subjective scores)and radiation dose (CTDIvol,DLP,ED,efffctivemAs) between the two groups were compared.(3)30patients were randomly divided into group C, it underwent temporal bone HRCT with CARE KV and FBP and Safire(1-5) reconstruction technique,the different ways of reconstruction image quality,the average CT value and image noise, SNR, CNR were analyzed.(4)60patients underwent temporal bone HRCT scanning were randomly divided into two groups. GroupD(30patients) underwent temporal bone HRCT with100kV、180mAs and CARE KV and Safire(3) reconstruction technique, groupE(30patients) with80kV、180mAs and CARE KV and Safire(3) reconstruction technique.Plus group A and group B The imaging quality(mean CT value, image noise, SNR, CNR, subjective scores) and radiation dose (CTDIyol,DLP,ED) between the four groups were compared.Results(1) When the tube voltage was fixed,the relation between CTDIvol and tube current was the linear correlation The radition dose was significantly reduced, image noise increases as the tube current decreased, as tube current was same. When using different tube voltage scanning, radition dose is different,the relation between the radition dose and kV was exponential correlation. Such as when the preset tube current of180mAs,100kV radiation dose was120kV reduced about38.6%, but the noise was not obvious;When the preset tube current of180mAs,tube voltage reduced to80kV, radiation dose reduced about47.3%. When tube voltage was120kV, the tube current was reduced to30mAs. SAFIRE reconstruction noise place were significantly lower than FBP reconstruction. When tube voltage was100kV, the tube current was reduced to30mAs too,but image noise was high. When tube voltage was80kVbut when the tube current fell to120mAs, tube voltage was80kV,the image began to appear sclerosing artifacts, image quality was middle. When reduced to70kV, no matter how much the preset tube current in a large number of sclerosing artifacts, affected the image quality, and obvious tube current was added, and maintained a certain numerical constant, radiation dose did not significantly drop, and even higher than80kv,120mAs.(2) the difference of the image quality(The average CT value,image noise, SNR, CNR, subjective scoring)was not statistically significant between group A and group B(P>0.05); the difference of DLP,ED was statistically significant between the two groups (P<0.05).Compared with group A,the average(DLP) decreased by12.71%.and ED decreased by12.85%,the subjecrive scores of image quality were all over2.9.(3) group C underwent temporal bone HRCT with FBP and Safire(1-5) reconstruction technique,to compare with reconstruction by FBP, for the noise, Safire(1-5) reconstruction technique decreased to23.1%,39.2%,42.4%,54.1%,61.2%individually; for the SNR, it increased to26.6%,40.0%,71.1%,117.7%,153.3%. the difference was statistically significant (P<0.05). For the images of FBP、Safire, the difference of the image subjective scoring was statistically significant (P<0.05), for the images of Safirel-5,the image subjective scoring is higher than that by FBP; for the images of Safire2-4, the image subjective scoring is not statistically significant; and it is the highest for the images of Safire-3. but for the rate of lesion detection, all the images were the same.(4) For CTDIvol、DLP、ED,the difference of statistically significant was found between groupA,groupB,groupC,groupD,groupE,respectively(P<0.05).the difference of CTDIvol, DLP, ED was not statistically significant between groupB and groupC(P>0.05), the difference of CTDIvol,DLP,ED was statistically significant between groupB and groupD,groupD and group E,groupB and groupE(P<0.05).Compared with group B,the CTDIvol of groupD decreased by17.3%,the DLP、ED decreased by24.4%、23.8%. The CTDIvol、DLP、ED of groupE decreased by34.9%,43.5%、41%;Compared with group D, the CTDIvol. DLP、ED of groupE decreased by21.4%,25.2%.22.6%.Compared with group B, the CTDIvol、DLP、ED of groupE decreased by34.9%,43.6%、41.5%.(5) No significant difference of the mean score and the average CT value were found between groupA,groupB,groupC,groupD,groupE respectively(P>0.05). the average CT value of group E is higher.For image noise, SNR,CNR the difference was statistically significant in five groups, respectively(P<0.05).the difference of noise,SNR,CNR was statistically significant between groupB and groupC(P<0.05). Compared with group C,the noise decreased by34.1%,and CNR、SNR increased by32.6%、37.8%.No significant difference of the average CT value and CNR were found between groupC and groupDrespectively(P>0.05),the difference of noise,SNRwas statistically significant (P<0.05). Compared with group C,the noise decreased by14%,and SNR increased by31%.no significant difference of the average CT value,noise,SNR,CNR were found between groupC and groupE,respectively(P>0.05),no significant difference of the average CT value was found between groupD and groupE respectively(P>0.05),the difference of noise,SNR,CNRwas statistically significant (P＜0.05). Compared with group E,the noise of groupD decreased by14%,and SNR、CNR increased by18.0%、30.3%. Compared with group E,the noise of groupB decreased by32.3%,and SNR、 CNR increased by31.5%、85.6%.Conclusion(1) The CT low-does scanning protocol could be used by low mAs or low kV in the temporal bone scanning with Siemens Somatom Definition FLASH CT. Seted the reference voltage120kV, reference current120mAs, FBP reconstruction, in order to obtain high quality image quality.When tube voltage was120kV, the tube current was reduced to30mAs.When tube voltage was100kV, the tube current was reduced to40mAs. When tube voltage was80kV more than180mAs tube current should be set in.70kv could not be used in temporal bone scan.but SAFIRE reconstruction, To get high quality image, can reduce the scanning condi-tions(2) For temporal bone HRCT scanning, CARE KV combined techniques not only promises high quality images,but also decreases the radiation doses.ED fell about12.85%.(3) The SAFIRE reconstruction can decrease effectively the noise and increase the image quality for the the temporal bone high resolution scan.Compared FBP reconstruction, image noise reduced34.1%, SNR, CNR increased by32.6%and37.8%respectively It can Reduce the temporal bone high resolution radiation.(4) The application of low kV and Safire reconstruction technique and CARE kV in FLASH CT temporal bone high resolution scan can significantly reduce radiation dose.The scan protocol can substantially reduce radiation doses while preserve good diagnostic image quality. Part II The inner ear bony structure measurement of mild sensorineural hearing loss with Dual-Source CTObjectiveOur study was to explore the structures of normal children reliable morphologic parameters of innear ear measurements, and to explore the mild sensorineural hearing loss and normal children patients with the inner ear bony structure numerical compare whether there was a difference between, gender;left, right measurements.Materials and MethodsChildren (age<14years):normal children as control group, suffered from mild congenital sensorineural hearing loss (excluding standard for Mondini deformity, Michel deformity, cochlear dysplasia,vestibulun deformity,semicircular canal deformity,enlarged aquaeductus vestibuli, internal auditory cannal narrow), as the experimental group, the male43cases, fem-ale in45cases, age range1-13, with an average age of6.52±1.03. Inner ear bony structure by two familiar with temporal bone anatomy doctors measurement, measured left and right ear bony structure (anterior semicircular canal, lateral and posterior semicircular canal bone island area and cochlear width, height, the width ofthe bony canal for the cochlear nerve) twice, take the left, the right side of the average, compared two physicians the consistency of the results, compare the control group, experimental group results whether there was a difference, compared results if there was a difference between gender.Results(1) Two physicians respectively measure bony structure measurement results were in good correlation analysis in the inner ear(P>0.05,r>0.89). (2) the difference of experimental group and control group inner ear bony structure measured values between left and right ear was no statistically significant (P>0.05).Control group, experimental group in the inner ear bony structure measured values were no statistical difference between gender(P>0.05).(3) the experimental group of anterior, lateral and posterior semicircular canal bone island area, the CW, CH, WCN measured values are less thean the control group; Two groups of comparisons, the anterior, lateral and posterior semicircular canal bone island area, the CW, CH difference was statistically significant (P<0.05), there was no statistical significance (P>0.05) difference WCN.Conclusion(1) The lateral and posterior semicircular canal bone island area, the CW, CH measured values of suffering from mild congenital sensorineural hearing loss are less thean normal children, for CT in the diagnosis of congenital sensorineural hearing loss provides a quantitative method.(2) In the study,the control group of the inner ear morphologic parameters can be used as a reliable normal children inner ear morphologic parameters...