Coronary Multislice Spiral Ct Imaging Technology And Clinical Applications

PART ONETechnical study of coronary angiography with multislice helical computed tomography Objective: to investigate the factors that could influence the quality of coronary angiography with multislice helical computed tomography(MSCT). Methods: A total of 85 consecutive patients were studied by MSCT. The coronary axial images were reconstructed by retrospective ECG-gated technique. First of all, the patients were divided into three groups according to the scan pitches which were 0.375,0.5 and 0.625,then each group was divided into four subgroups by the patient heart beat rate, which were ≦60bpm,61～70bpm,71～80bpm and ﹥80bpm respectively. The image qualities of the four groups were evaluated and scored by two radiologists. The scores of all groups were statistically compared with each other. Results: The difference of coronary image qualities was not statistically significant between the ≦60bpm group and 61～70bpm (P>0.05).The same result was also found between 71～80bpm group and ≧80bpm.while the relative lower rate of heart groups(≦60bpm and 61～70bpm) compared with relative higher (71～80bpm and ≧80bpm),the differences of the image quality were statistically significant(P<0.O5). Among the different pitch groups, the image quality of smaller pitch group was better than that of larger one. The image of 0.375 pitch was the best of all. And it was better with 0.5 pitch than 0.625 pitch. The artifacts of the images reconstructed in phases of 40%～80% R-R cycle were less than the other phases. The image reconsctructed with both VR and CPR methods were better than thant with MIP method. Conclusion: The motion artifact due to heartbeat is the most important factor that influences the quality of coronary MSCT image. The lower heartbeat rate, the better is the quality of coronary image. The small pitch scan can improve the quality of the coronary MSCT image byreducing motion artifact. Key words: Tomography,X-ray computed,Coronary angiography...