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 do
2、sage 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:
3、Improved 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 scanProspective
4、ly ECG-triggered 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 Heli
5、cal Technique: 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
6、scan after scanStep & Shoot 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=
7、0.21mSvCase of low dose-Prospectively 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
8、 heart rate14Air Propelled Ferry 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
9、 J, Toh KH. J Cardiovasc Comput 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
10、beat scan10% to end of R-R interval4-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-Gated
11、CPR of RCA18Case of high heart rate-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
