Application of dual-source spiral CT with high-pitch flash mode in CT pulmonary angiography

Abstract:

Objective：To explore the feasibility of dual-source spiral CT with high-pitch flash spiral mode as well as time-density curve in diagnosing the clinically suspected pulmonary embolism（PE）. Methods：Sixty patients planed to receive CT pulmonary an－giography（CTPA） were randomly divided into two groups. Routine scan and bolus tracking monitoring were used in control group，while dual-source spiral CT with high-pitch flash spiral mode as well as time-density curve was used in experimental group. Contrast agents Iodine diftler with the concentration of 400 mgI/ml was applied in both groups. The parameter of CT scanning was the same in both groups. All CT original dates were transferred to Siemens workstation and were post-processed by VR，MIP，MPR and CPR tech－nology. The CTPA image quality was evaluated based on score of image quality，CT value，and contrast to noise ratio（CNR）. Results：All patients in two groups completed CTPA successfully. There was no difference in baseline characters including sex，age，height and weight between the two groups（P=0.752，0.605，0.319，0.523）. CNR of experimental group was higher than that of control group（P=0.028，0.030，0.001，0.012，0.020）. There was no difference in CT value of pulmonary artery trunk，RSPA，RIPA，LSPA and LIPA between the two groups（P=0.362，0.986，0.373，0.584，0.931），but CT value of the ascending aorta，RSPV，RIPV，LSPV and LIPV were lower in experimental group than in control group（P=0.000，0.001，0.000，0.003，0.000）. Scores of image quality were better in experimental group than in control group（χ2=12.25，P=0.016； χ2=7.53，P=0.023）. Both the contrast agents（24 ml vs. 50 ml） and radi－ation dose[（5.27±1.94） mSv vs. （7.30±2.73） mSv] were lower in experimental group than in control group（P=0.011）. The scanning time was significantly shorter in experimental group than in control group[（0.94±0.07） s vs. （4.71±0.37） s，P=0.000）]. Conclusion：CTPA with flash spiral mode and time-density curve could col－lect the satisfied image，reduce patients’ contrast agents and radiation dose，and decrease the breathless time.