Bouchra Habib Geryes1, Raphael Calmon2, Victoria Donciu2, Diala Khraiche3, Karine Warin-Fresse4, Damien Bonnet5, Nathalie Boddaert2, Francesca Raimondi6. 1. Hôpital Universitaire Necker Enfants Malades, Service de Radiologie pédiatrique, 149, rue de Sèvres, 75743 Paris Cedex 15, France. Electronic address: bouchra.habib-geryes@aphp.fr. 2. Hôpital Universitaire Necker Enfants Malades, Service de Radiologie pédiatrique, 149, rue de Sèvres, 75743 Paris Cedex 15, France. 3. Hôpital Universitaire Necker Enfants Malades, Unité Médico-Chirurgicale de Cardiologie Congénitale et Pédiatrique, 149, rue de Sèvres, 75743 Paris Cedex 15, France. 4. Imagerie Cardiovasculaire, Centre Hospitalier Universitaire de Nantes, Blv Jacques Monod, 44093 Nantes, France. 5. Unité Médico-Chirurgicale de Cardiologie Congénitale et Pédiatrique, Centre de référence Malformations Cardiaques Congénitales Complexes - M3C, 149, rue de Sèvres, 75743 Paris Cedex 15, France; Université Paris Descartes, Sorbonne Paris Cité, France. 6. Hôpital Universitaire Necker Enfants Malades, Service de Radiologie pédiatrique, Unité Médico-Chirurgicale de Cardiologie Congénitale et Pédiatrique, 149, rue de Sèvres, 75743 Paris Cedex 15, France.
Abstract
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.
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.