1、Application of 256-slice CT Application of 256-slice CT in coronary CTAin coronary CTAApplication of 256-slice CT in coronary CTA2CTA with Reduced Radiation DoseCTA with high heart rateReduced Radiation Dose364-slice:15-20mSv-7501000 Chest film4Reduced Radiation DoseReported effective radiation dosa
2、ge in recent studies with the use of 64detector row CT have ranged from 9.5 to 21.4 mSv,more than the previously reported d-oses from 16detector row CT studies.James P,Elise L,Bruce A,et al.Prospectively Gated Transverse Coronary CT Angiography versus Retrospectively Gated Helical Technique:Improved
3、 Image Quality and Reduced Radiation Dose.Radiology 2008;246:742-75316-detector64-detector256-detectorMore doseage？More doseage5Reduced Radiation Dose530-46%12-24%17-33%80%3 multiple3 multipleDoseWise provedproved New32-40%6Reduced Radiation DoseRetrospectively ECG-triggered scanProspectively ECG-tr
4、iggered scanProspectively gated transverse CT technique represents an 83%reduction as compared with that for the group with the retrospectively gated helical technique。James P,Elise L,Bruce A,et al.Prospectively Gated Transverse Coronary CT Angiography versus Retrospectively Gated Helical Technique:
5、Improved Image Quality and Reduced Radiation Dose.Radiology 2008;246:742-7537Reduced Radiation Dose7 Larger coverage:80 mm For a typical cardiac scan(120 mm)Two axial shots 3 Heart beats 4-5 second scans Less vulnerability to irregularity/arrhythmia More reliable performance in scan after scanStep&S
6、hoot Cardiac scan1Step:23256slice320sliceReduced Radiation Dose a b c d e 图像区图像区SpiralOverscanReduced Radiation Dose10Patient:CT检查时条件设置检查时条件设置 Xiong shu yan,woman,46Height:162mm,Weight：52KGBMI：19.8Symptom：chest painRadiation doseCTDIvol*Scan Length*0.0141.4mGy*11.04*0.014=0.21mSvCase of low dose-Pro
7、spectively ECG-Gated5 Chest films11Case of low dose-prorospectively ECG-GatedCPR of LAD12Case of high heart rate-Retrospectively ECG-GatedCPR of LCX and RCA13Reduced Radiation DoseHoe J,Toh KH.J Cardiovasc Comput Tomog.2009;3:257-261.Prospective 320-slice scanning14High heart rate14Air Propelled Fer
8、ry Hovercraft Hovercraft OperationOperationCompressed Air Cushion lifts the ferry above seCompressed Air Cushion lifts the ferry above sea level and a conventional motor moves it forwaa level and a conventional motor moves it forward rd 0.27 0.27S S 15High heart rateHoe J,Toh KH.J Cardiovasc Comput
9、Tomog.2009;3:257-261.ScanScan acquisition parameters with 256-slice MDCT acquisition parameters with 256-slice MDCTHeartHeart rate rateExposure controlExposure controlExposure phase windowExposure phase windowDataData recomstructionrecomstruction mode mode1782-heart beat scan10%to end of R-R interva
10、l4-segment reconstruction0.27S0.27S0.35S0.35S16Patient Parameters of CT scan Ceng wen,femal,47 years.symptom：discomfort in the chest Case of high heart rate-Retrospectively ECG-GatedWeight：55KGHeight：160mm BMI：21.517Case of high heart rate-Retrospectively ECG-GatedCPR of RCA18Case of high heart rate
11、-Retrospectively ECG-GatedMPR of RCA and CT value19Case of high heart rate-Retrospectively ECG-GatedCPR of LADCPR of LCXCPR of DCPR of PDA20Patient Parameters of CT scan Liu hui zhen,femal,57 years.symptom：discomfort in the chest Case of high heart rate-Prospectively ECG-GatedWeight：58KGHeight：164cm BMI：21.621Case of high heart rate-Prospectively ECG-GatedCPR of LCX22Case of high heart rate-Prospectively ECG-GatedCPR of LCXCPR of LADCPR of MCPR of D+Why?70%cases30%casesDiagnosisCureWhy?30%70%Diagnosis Cure Thank you for your attention!2009.10.30
