Assessment of coronary artery by prospective ECG-triggered 256 multi-slice CT on children with congenital heart disease

Coronary computed tomography angiography in children

Imaging the coronary arteries of children, with their faster heart rates, small vessel size and common inability to lie still or breath-hold, has been a major challenge. With numerous advances in technology, CT examinations can now be performed quickly, often with children free-breathing and with much lower radiation doses than previously. This has led to increased use in children. Care must be taken with technique and choice of electrocardiogram (ECG)-gating technique to obtain adequate imaging for a diagnosis while keeping radiation dose as low as reasonably achievable (ALARA). In this paper, we discuss techniques and tips for CT imaging of the coronary arteries in children, including use of dual-source- and ultrawide-detector CT scanners.

Application of prospective ECG-gated multiphase scanning for coronary CT in children with different heart rates

BACKGROUND

To investigate the application of prospective ECG-gated multiphase scanning in coronary CT imaging in children with different heart rates.

METHODS

In the control group, 160 children aged 2-4 years who underwent a coronary CT examination in our hospital from May 2016 to December 2017 were retrospectively selected. They were divided into five subgroups according to their heart rate frequency: 75-85 beats/min, 86-95 beats/min, 96-105 beats/min, and 106-120 beats/min. There were 40 children in each subgroup. Each child was treated with retrospective ECG-gated scanning technology. Six groups of phase images were reconstructed: 40%, 45%, 50%, 70%, 75% and 80%. The optimal phase was selected for coronary artery reconstruction. In the study group, 240 children aged 2-4 years who underwent coronary artery CT examination in our hospital from January 2018 to May 2019 were prospectively selected and divided into five subgroups according to the heart rate frequency: 75-85 beats/min, 86-95 beats/min, 96-105 beats/min, and 106-120 beats/min. There were 60 children in each subgroup. A prospective ECG-gated multiphase scanning technique was used to reconstruct 70%, 75% and 80% phase images in the subgroups with heart rates < 85/min. In the remaining subgroups, 40%, 45% and 50% phase images were reconstructed, and the optimal phase was selected for coronary artery reconstruction. The scanning parameters, dosage of contrast medium and injection mode of contrast medium were the same in both groups. The radiation dose and image quality of the coronary artery were compared between the two groups at the same heart rate.

RESULTS

When comparing the two groups at the same heart rate, the radiation dose in the study group was 72% lower than that in the control group (P < 0.05). There was no significant difference in coronary artery image quality between the two groups at the optimal phase (P > 0.05).

CONCLUSIONS

Applying prospective ECG-gated multiphase scanning technology to children's coronary CT imaging can significantly reduce the scanning radiation dose without affecting the quality of the coronary artery image.

Stereo information of skeletal data based on CT sequence medical images

In order to study the three-dimensional information of skeletal data from CT (Computed Tomography) serial medical images, 100 cases of distal posterior tibial fracture were selected, X-ray films of ankle joint were taken, and plain CT scan and three-dimensional reconstruction were performed to evaluate the fracture situation. According to the CT images, the cases were divided into posterior Pilon fracture and posterior ankle fracture. The results showed that Pilon fracture accounted for 62% and there were 39 males and 23 females, 32 left and 30 right. There were 38 cases of posterior ankle fracture, 28 males and 10 females, 20 left and 18 right. There were many types and forms of posterior Pilon fracture and posterior ankle fracture. It showed that the main cause of distal posterior tibial fracture is violence. Axial violence of tibia or torsional violence of lower limbs often causes Pilon fracture. Avulsion fracture caused by torsional violence mostly belongs to posterior ankle fracture. To sum up, stereoscopic information of bone data was obtained through CT images of tibia.