Мультиспиральная компьютерная томография сердца: оптимизация протокола сканирования при проведении неинвазивного картирования сердца перед катетерной абляцией фибрилляции предсердий

Purpose: to develop optimal technique of cardiac multidetector computed tomography (MDCT) before noninvasive cardiac mapping before cateter ablation of atrial fibrillation. Materials and methods. 94 patients with atrial fibrillation were included in study (60 males, 34 females; mean age = 58.3 ± 10 years; mean body mass index (BMI) = 29.9 ± ± 4.8). The patients were divided into 2 groups: I – 80 patients who underwent computer tomography (CT)-protocol for noninvasive cardiac mapping with standard contrast enhancement (single-bolus protocol); II – 14 patients who underwent CT with modified contrast enhancement technique with preliminary contrast injection (prebolus). To detect thrombotic masses in the left auricle the low-dose delayed phase was performed. The analysis of individual features of pulmonary veins, left atrium and adjacent structures was performed. Contrast enhancement of heart chambers was assessed by mean attenuation and homogeneity measurement. Results and discussion. The typical anatomy of the right pulmonary veins was in 93.6% of cases; right middle pulmonary vein in 5.3%; right segmental veins in 1.1%. The typical anatomy at the left side was in 57.4% of cases; common vestibulum of the left pulmonary veins in 18.1%; common left trunk in 24.5%. Volume enlargement of the left atrium (LA) was in 96.8% of patients. In 6 cases left auricle thrombosis was suspected, low-dose delayed phase was performed. In 2 cases filling defects in left auricle persisted, thrombosis was proved by transesophageal echocardiography. With the single-bolus injection protocol the contrast enhancement of left heart chambers was best (mean attenuation of blood in LA = 296 ± 84 HU, in left ventricle (LV) = 286 ± 83 HU), but the contrast enhancement and homogeneity of the chambers were insufficient (mean attenuation of blood in right atrium (RA) = 179 ± 97 HU, in right ventricle (RV) = 176 ± 80 HU). With prebolus protocol the contrast enhancement and homogeneity of all chambers were optimal (mean attenuation of blood in LA = 259 ± 31 HU, in LV = 286 ± 83 HU, in RA = 270 ± 92 HU, in RV = 253 ± 80 HU). This allowed making more accurate epi-endocardial heart models in the noninvasive cardiac mapping and operation planning. Conclusion. MDCT with standard contrast enhancement protocol provides detailed information about anatomy and size of pulmonary veins, the left atrium volume, the presence of intracardiac masses (including thrombotic masses), the anatomy of adjacent structures. The modified contrast enhancement technique with preliminary contrast injection (prebolus) allows to receive optimal contrast enhancement of all heart chambers and to make high accurate epi-endocardial models of both the right and left sides of the heart in case of noninvasive cardiac mapping.