论文部分内容阅读
目的评估容积 CT(VCT)心脏扫描时,开启或关闭心电图(ECG)调制电流(mA)技术对图像质量是否有影响,并判断 ECG 调制 mA 技术是否能有效降低曝光剂量。方法将跳动心脏模具设定为高、中、低不同速率的稳定心率,采用与不同速率稳定心率相匹配的重组算法,开启 ECG 调制 mA,对心脏模具进行扫描,扫描同时记录各扫描序列的曝光剂量,在采集到的图像中选取结构均匀的部位,测量该部位的 CT 值及不同部位 CT 值的差值,并记录图像测量部位的标准差(s)值;关闭ECG 调制 mA,重复上述扫描并记录曝光剂量,对采集到的图像进行相同测量和记录。将2次扫描所测得的数据进行统计学分析。结果在同样心率条件下,ECG 调制开启时比关闭时曝光剂量有明显减低,在每分钟搏动数(bpm)为50、60、75和95的4种心率条件下,曝光剂量分别减少了48.0%、44.0%、37.0%和37.7%;2组图像的数据分析差异无统计学意义(P>0.05)。结论 VCT 心脏扫描时,开启 ECG 调制 mA 技术能够有效降低曝光剂量,同时对图像质量无明显影响。
Objectives To assess whether ECG modulated current (mA) technology can have an impact on the image quality during a volumetric CT (VCT) cardiac scan and to determine whether the ECG modulated mA technique can effectively reduce the exposure dose. Methods The beating heart model was set as stable heart rate at different rates of high, medium and low. Using a recombination algorithm matched with stable heart rates at different rates, the ECG modulated mA was turned on to scan the heart mold and record the exposure of each scanning sequence Dose in the collected images, select the site of uniform structure, measure the CT value of the site and the difference between the CT values of different sites, and record the standard deviation of the image measurement site (s) value; turn off ECG modulation mA, repeat the scan And record the exposure dose, the collected images were measured and recorded the same. The data from 2 scans were statistically analyzed. Results At the same heart rate, the exposure dose was significantly reduced when the ECG modulation was turned on than when it was switched off. The exposure dose was reduced by 48.0% at the four heart rates of 50, 60, 75 and 95 beats per minute (bpm) , 44.0%, 37.0% and 37.7% respectively. There was no significant difference between the two groups (P> 0.05). Conclusions When VCT is used in cardiac scanning, turning on the ECG modulation mA technique can effectively reduce the exposure dose without affecting the image quality significantly.