Low-dose paediatric cardiac and thoracic computed tomography with prospective triggering: Is it possible at any heart rate?
OBJECTIVE
To demonstrate that the use of step-and-shoot (SAS) mode in paediatric cardiac CT angiography (CCTA) is possible at heart rates (HR) greater than 65 bpm, allowing low-dose acquisition with single-source 64-slices CT.


METHODS
We retrospectively included 125 paediatric patients (0-6 years). CCTA was performed with SAS at diastolic phase in 31 patients (group D, HR < 65 bpm), at systolic phase in 45 patients (group S, HR ≥ 65 bpm) and with non-gated mode in 49 patients (group NG). Effective dose (ED) and image quality using a 3-grade scoring scale (1, excellent; 2, moderate; 3, insufficient) of group S were compared with group D for coronary examinations and group NG for entire thorax vascular anatomy.


RESULTS
For coronary indications, median ED was 0.6 mSv in group D versus 0.9 mSv in group S (p < 0.01). For whole thorax indications, median ED was 2.7 mSv in group NG versus 1.1 mSv in group S (p < 0.001). The mean image quality score was (1.4 ± 0.6) points in group D, (1.4 ± 0.7) in group S for coronary indications (p = 0.9), (1.3 ± 0.6) in group S for whole thorax indications and (2.0 ± 0.0) in group NG (p < 0.001).


CONCLUSION
SAS mode is feasible in children with HR greater than 65 bpm allowing low-dose CCTA. It provided comparable image quality in systole, compared to diastole. SAS at the systolic phase provided better image quality with less radiation dose compared to non-gated scans for whole thorax examinations.
['Habib Geryes|Bouchra|B|', 'Calmon|Raphael|R|', 'Donciu|Victoria|V|', 'Khraiche|Diala|D|', 'Warin-Fresse|Karine|K|', 'Bonnet|Damien|D|', 'Boddaert|Nathalie|N|', 'Raimondi|Francesca|F|']
D002648:Child D002675:Child, Preschool D005260:Female D006321:Heart D006339:Heart Rate D006801:Humans D007223:Infant D007231:Infant, Newborn D008297:Male D011446:Prospective Studies D011829:Radiation Dosage D000069079:Radiation Exposure D013902:Radiography, Thoracic D014057:Tomography, X-Ray Computed
Paediatric Prospective triggering Congenital heart disease Coronary CT angiography Step and shoot