z-bio 2021-06-24 395

　　Goal: How to develop a sequence to reduce image respiration and heart rate artifacts in 256-slice spiral CT in vivo chest CT scans in rats?

　　Method: Do you use Philips Brilliance-iCT to perform chest CT imaging on 10 SD rats? Two scanning methods are used for each rat: A and B. Method A is the traditional chest CT scan sequence for non-ECG spiral scanning mode, and method B is non-ECG axis scanning mode? In both groups, under the condition of 120 kV, the collected CT data were reconstructed with 8 cm scan length of the transverse and coronary lung window and soft tissue window, and observed and measured images, and observed and measured images. The average CT value of the two sets of images. The difference in signal-to-noise ratio (SNR) and subjective image quality scores, and the consistency of subjective image quality scores between different observers?

　　Result: Analyze the chest CT scan data of 10 rats? One kind? B. Dose length The product of the two scan sequences (dose length product, DLP) is 144.7 mGy/cm and 72.2 mGy/cm, respectively. There are significant differences in the CT values of lung tissue and liver tissue. There is no group (t value is -0.205～0.545, P→0.05), and there are differences in image noise between the two groups. No significance (t value -0.865, P→0.05), no significant difference in SNR. In the image, there are two groups of lung tissues (t-value 0.903, P→0.05), but the SNR value of liver tissue of group B is higher than that of group A, the difference is significant (t-value is -2.885), Pu003c 0.05)? The correlation coefficient of the scores of the two doctors was 0.763, and the diagnosis results were in good agreement. Are the subjective quality scores of the two scanning methods A and B (2.5±0.53) points? (4.3±0.67) points, the difference is significant (χ2 value is 14.76, Pu003c0.05)?

　　Conclusion: The rat chest CT scan using the non-ECG portal axis scan mode can be compared with the conventional chest CT scan (non-ECG portal spiral scan). Mode) is the CT value and noise? Although similar to the signal-to-noise ratio, the non-cardiac portal axis scan mode can effectively reduce the breathing and heartbeat artifacts in the rat chest image and reduce the radiation dose. , How to improve image quality and improve the reliability of observer diagnosis?