Feasibility Of Prospective Ecg-gated Step-and-shoot Scanning During Narrow R-R Interphase In The Coronary CT Angiography With Dual Source Flash Ct

ObjectiveTo investigate the feasibility of coronary artery imaging by dual source flash CTnarrowing the exposure time window and analyze its differences of accuracy, image qualityand radiation dose with the control group.Materials and Methods200patients (body mass index (BMI) was23-25kg/m2,sinus and changes in heartrate≤10bmp) that underwent coronary artery imaging with prospective ECG-gatedacquisition in our hospital were randomly divided into2groups with100cases in eachgroup,100patients (56male,44female;age range,36-74years; average age,49.2±11.5years)were included in experimental group. The control group consisted of100patients(61male,38female; age range,35～72years;average age,54.3±11.5years).There were53patients inthe experimental group that underwent coronary angiography (SCAG)while51patients inthe control group. Data acquisition phase differs from the heart rate. For the experimentalgroup, when the heart rate was slower than75bmp,65%~75%RR interval of exposurewas chosen; conversely, if heart rate was faster than75bmp,35%~45%RR interval waschosen;35%~70%RR interval exposure was chosen in all patients in control group. Tubevoltage was adjusted according to the body weight mass index (BMI):it was120kV Whenthe BMI is23~25kg/m2. The tube current was adjusted through the the care dose4Dautomatically. Image quality of coronary arteries and degree of stenosis was analyzed bytwo radiologists with double blind method. SPSS13.0statistical software was applied.There was statistically significant when P <0.05. Observers evaluated whether there wasstatistically significant difference in image quality, radiation dose (mSv) and accuracy between the two groups.Results200patients underwent coronary artery imaging by prospective ECG-gatedacquisition successfully. In53cases from the experimental group that underwent SCAGexamination, the positive diagnostic accuracy rate was92.45%while it was90.20%inthe control group. There was no significant difference between the image quality. Meaneffective dose was significantly lower (p<0.05) in the experimental group(3.01±0.45mSv)compared to the control group((6.91±0.38mSv).ConclusionThe use of flash dual-energy flash CT with prospective ECG-gated acquisition andnarrow RR interval of exposure allows for significant dose reduction with image qualityavailable for diagnose. The consistency of the positive diagnostic accuracy rate between itand SCAG was good.