| objective:Through the comparative study of clinical effect,comparison of photon detector in Stellar detector,dual-source CT and individual contrast injection protocol with conventional contrast agent injection protocol on image quality and radiation dose,efficacy and safety evaluation of imaging technology,clinical application of cervical vascular imaging protocol for the next step of the selection guide.Method:Collected during the period of September 2015-January 2017 for head and neck artery disease in clinical suspicion,line need to patients with head and neck CTA inspection,all patients were underwent CTA by the Stellar photon detector dual-source CT.exclusion criteria: allergy to contrast agent,and in a coma,and so on and so forth,eventually to be included in the 156 patients included in this study.The subjects were carried out in accordance with the random indicator method randomized,control group: conventional contrast medium injection protocol was adopted,the experimental group: personalized contrast medium injection protocol was adopted,78 patients in each group.For all patients,Stellar photon detector dual-source CT head and neck CTA were performed,4 h told fasting patients before inspection,inspection against the possible because of the adverse reaction of contrast medium used for interpretation,especially entrust inspection after a large number of drinking water,to promote the discharge of contrast medium.Patients with conventional right elbow in the middle of establishing vein channels,suspected diagnosis of subclavian artery lesions,the foot dorsal vein to establish vein channels,and iodine allergy experiments before the inspection.Before inspection,remove activities denture metal foreign body,such as scanning Angle and listen to theorbital line parallel,set up to ensure that patients with stable vital signs,using preheated contrast agent in advance,in double cylinder of high pressure syringe.Injecting the syringe by elbow vein puncture,USES the group note tracking technology,trigger the monitoring level in the main pulmonary artery branch level descending aorta,delay 10 s begin to collect data,trigger threshold is set to 100 HU,after reaching the threshold 2 s delay scan.Scan parameters of the experimental group: tube voltage: 100 kV,Care dosed 4D was used to automatically adjust the tube current,tube rotation speed: 0.2 s/r,collimator width:2×128×0.6 mm,pitch: 0.7.Contrast medium injection time fixed for 10 s,45 kg or less of patients injection rate is 4.0 ml/s,based on 45 kg,the weight,every 10 kg increase injection rate increased by 0.5 ml/s.Volume of contrast agent = injection rate × injection time(s).Scan parameters of the control group:tube voltage: 120 kV,Care dosed 4D was used to automatically adjust the tube current,tube rotation speed: 0.2 s/r,collimator width:2×128×0.6 mm,pitch: 0.7.Fixed volume of contrast agent(60 ml)and contrast medium injection rate(4.0 ml/s),the regiment note Tracking(Bolus Tracking)intelligent trigger scanning mode.Trigger point,scanning direction and scope of consistent with the experimental group.Through statistics of two groups of patients with imaging quality of imaging examination,comparing the effective conditions and through the statistics of two groups of patients with radiation dose,the potential risk compared with security check,two imaging examination in an integrated the merits of the clinical application of differences.The imaging quality using both subjective and objective evaluation.Objective image quality evaluation system for the measured value,the image signal-to-noise ratio(SNR)were obtained through the calculation and contrast to noise ratio(CNR)were statistically analyzed.A subjective assessment by two professional image practitioner,according to the standard for all four 4-point scale image quality on subjective image quality score.Records of radiation dose of CT scanners automatically generated parameters,including CT dose index(CTDI vol),product of dose length(DLP),and calculate the effective radiation dose(ED);On two groups of patients with radiation dose parameters and contrast agent were analyzed.Our institute with the measurement data of using independent sample t-test,count data by chi-square test,the consistency of the subjective image quality score with kappa test.Result:1.Study of two groups of patients with objective image quality control,numericalcontrol group of parts of SNR group AOAR 19.6±9.6,38.8±10.6 in the observation group,the control group of parts of SNR numerical CCA 20.3±10.3,41.8±11.5 in the observation group,the control group of parts of SNR numerical ICA 16.8±16.7,31.4±17.2 in the observation group,numerical MCA-M1 site SNR the control group is 13.6±11.5,22.5±16.3 in observation group.control group SNR numerical average of 17.6±10.8,the observation group average of The observation group is 33.6±13.6,SNR values were significantly higher than control group.(P<0.01).CNR numerical calculation,CNR>8 that the image can be assessed for quality,in this study,CNR >8.were the observation group and the control group were higher than those of the various parts of the CNR value of 8points,according to which parts of the CNR group of AOAR numerical control group 17.1±6.3,observation group 32.1±8.1,CCA numerical part of CNR control group 15.9±5.4,35.9±10.7 in observation group,CNR control group 15.5±10.8 ICA numerical position,25.5±10 in the observation group,The site of MCA-M1 CNR numerical control group11.2±6.7,18.2±8.5 observation group.control group CNR numerical average of 14.9±5.9,27.9±6.8 average observation group,the observation group CNR values were compared with the control group,there was significant difference between the control group and the value is less than the observation group(P<0.01).2.Of the two groups of the subjective image quality of patients with the subjective image quality score for the image of the 2 senior radiologists respectively,the control group is 3.14±0.52,3.21±0.50,the average score of 3.17±0.52;the observation group was3.83±0.41,3.78±0.40,the average score of 3.81±0.41 imaging.2 the expert scoring evaluation of consistency is good,the control group kappa was 0.76,kappa value of observation group was 0.78,observation group of expert scores were significantly higher than control group(P<0.05),subjective image quality view The observation group was better than the control group.3.Evaluation of radiation dose,dose objective coefficient imaging equipment independent reference collection tips,control group CTDIvol,DLP,ED were 4.017±1.33 mGy,217.6±74.22 mGy cm 1.12±0.15 mSv,compared with the observation group CTDIvol,DLP,ED counts were 1.347±0.29 mGy,78.25±13.94mGy· cm,0.42±0.05 mSv,compared with the control group,the observation group contrast effective doses were lower than the control group 62.51%,and evaluation There was significant difference between the CT dose index and dose length product,while the observation group was significantly lower(P<0.05)4.The dose of contrast agent,the observation group the mean dose of contrast agent(49.1±5.4)ml,compared the average doses group was 60 mL,there was significant difference between two groups(t=4.583,P<0.05),the observation group contrast agent dose was significantly lower than the control group(10.8±2.1).Conclusion:Stellar detector,dual-source CT combined with personalized contrast agent injection protocol in head and neck CTA in contrast with conventional contrast agent injection protocol,can significantly reduce the dose of contrast agent,effectively reducing the radiation dose.The imaging quality of two kinds of inspection plan were better,but personalized contrast agent injection protocol can significantly improve SNR of images,while significantly reducing the value of CNR can significantly improve the quality of patients with vascular imaging,the imaging quality is more ideal,more conducive to the correct interpretation of clinicians imaging.So in the head and neck vascular diseases,using photon The detector dual source CT angiography combined with personalized contrast agent injection can reduce the dosage of contrast agent,reduce the radiation dose,and obtain the image quality to meet the diagnostic requirements... |
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