Visibility and image quality of peripheral pulmonary arteries in pulmonary embolism patients using free-breathing combined with a high-threshold bolus-triggering technique in CT pulmonary angiography.

OBJECTIVE: To investigate the visibility of peripheral pulmonary arteries by computed tomography pulmonary angiography (CTPA) and image quality using a free-breathing combined with a high-threshold bolus triggering technique and to explore the feasibility of this technique in pulmonary embolism (PE) patients who cannot hold their breath. METHODS: Patients with suspected PE who underwent CTPA (n=240) were randomly assigned to two groups: free-breathing (n=120) or breath-holding (n=120). RESULTS: The mean scanning time or visible pulmonary artery distal branches were not different between the groups. Mean CT main pulmonary artery (MPA) values, apical segment (S1), and posterior basal segment (S10) in the free-breathing group were higher compared with the breath-holding group. The subjective image quality score in the free-breathing group was higher compared with the breath-holding group. In the free-breathing group, no respiratory artifact was observed. In the breath-holding group, obvious respiratory artifacts were caused by severe chronic obstructive pulmonary disease (COPD), dyspnea, or other diseases that preclude patients from holding their breath. CONCLUSION: The free-breathing mode CTPA combined with a high-threshold bolus triggering technique can provide high quality images with a lower incidence of respiratory and cardiac motion artifacts, which is especially valuable for patients who cannot hold their breath.

Prognostic utility of coronary computed tomographic angiography: a 5-year follow-up in type 2 diabetes patients with suspected coronary artery disease.

OBJECTIVES: To analyze the predictive value of coronary computed tomography angiography on acute coronary artery events in patients with type 2 diabetes. METHODS: Coronary computed tomography angiography was performed in 250 type 2 diabetic patients. After a follow-up for 5 years, 145 patients were excluded as they did not have any coronary events. The remaining 95 patients were divided into study group and control group. According to their density and shape, the coronary artery plaques were classified into 3 types and 4 types, respectively. RESULTS: There is no statistically significant difference in the degree of stenosis between two groups. The proportion of calcified plaques in the study group was lower than in the control group. The proportion of mixed-calcified plaques in the study group was higher than in the other. Type III plaques have a 76.2% sensitivity and negative predictive value was 64.5% for acute coronary events; type IV plaques have a sensitivity of 52.6% and positive predictive value of 63% for chronic coronary events. CONCLUSIONS: CCTA may be used as a non-invasive modality for evaluating and predicting vulnerable coronary atherosclerosis plaques in patients with type 2 diabetes.

Value of multi-detector computed tomography angiography in predicting acute cardiac events in patients with type 2 diabetes.

The aim of the present study was to investigate the predictive value of multi-detector computed tomography angiography (MDCTA) on acute coronary artery events in patients with type 2 diabetes mellitus (T2DM). MDCTA was performed in 150 patients with T2DM (males, 74; mean age, 66±6.7 years for all patients) that had experienced atypical chest pains. After a follow-up period of at least 2 years, 55 patients were excluded from the study as they did not exhibit any coronary events. The remaining 95 patients were divided into the study group (n=28), that had experienced an acute coronary event such as acute coronary syndrome, or the control group (n=67) that had stable angina. There were no statistically significant differences in the degree of coronary artery lumen stenosis between the study and control groups (P=0.380). The proportion of calcified plaques in the study group was significantly lower compared with the control group (13.6 vs. 53.2%; P<0.001), while the proportion of soft plaques in the study group was significantly higher compared with the control group (37 vs. 9.3%; P<0.001). Type III plaques showed a sensitivity of 76.2% and a negative predictive value of 64.5% for acute coronary events. By contrast, type IV plaques had a sensitivity of 52.6% and a positive predictive value of 63% for chronic coronary events. Therefore, the results of the present study indicate that MDCTA may be used as a noninvasive modality for evaluating and predicting vulnerable coronary atherosclerosis plaques in patients with T2DM.