TRANSTHORACIC ECHOCARDIOGRAPHY, CARDIAC CT AND MRI IN PULMONARY ARTERIES ASSESSMENT IN CHILDREN WITH TETRALOGY OF FALLOT; [РОЛЬ ТРАНСТОРАКАЛЬНОЙ ЭХО-КГ, КТ И МРТ СЕРДЦА В ОЦЕНКЕ ЛЕГОЧНЫХ АРТЕРИЙ У ДЕТЕЙ С ТЕТРАДОЙ ФАЛЛО]

Purpose. To compare the capabilities of preoperative transthoracic echocardiography, CT, and cardiac MRI in determining and assessing the degree of the pulmonary artery system hypoplasia in children with Tetralogy of Fallot. Materials and Methods. The study comprised 72 children with Tetralogy of Fallot (TOF). The mean age of the patients was 8.5 (3.5; 8.5) months. All children underwent transthoracic echocardiography (TTE), 64 underwent cardiac CT, 30 underwent cardiac MRI, and 43 underwent conventional angiography. Morphometry of the main pulmonary artery, right and left pulmonary arteries in proximal and distal segments, calculation of z-score, Nakata and McGoon indices were performed on all diagnostic techniques. All results were compared with conventional angiography or intraoperative data. The interval between transthoracic echocardiography, CT and/or cardiac MRI and angiography or open surgery was less than 10 days. Hypoplasia of the left pulmonary artery and its branches was defined as a z-score deviation from normal values of less than (-2). An index value of Nakata less than 150 mm2/m2 and McGoon ratio less than 1.8 were considered contraindications for radical correction. Results. No statistically significant differences were found between the TTE, CT, and cardiac MRI with conventional angiography in morphometry of the main pulmonary artery and proximal segments of right and left pulmonary arteries, as well as z-score values (p >0,05). Significant differences were observed in the measurements of distal segments of left and right pulmonary arteries using TTE compared to CT, MRI, conventional angiography, and intraoperative data, with a significant underestimation of vessel diameters (p <0,05). No significant differences were found between CT, MRI, and conventional angiography or intraoperative data in assessing the diameters of distal branches of the left pulmonary artery. Both methods statistically insignificantly underestimated vessel diameters. Evaluating indexed parameters (McGoon and Nakata indices) using TTE results, statistically significant differences were identified compared to conventional angiography in the form of underestimated values (p <0,05). Comparison of McGoon ratio measurements between TTE and cardiac CT also revealed a statistically significant underestimation of the index by TTE (p <0,05). The calculated McGoon ratio from cardiac CT did not significantly differ from direct angiography data. The comparison of Nakata index measurements between TTE and cardiac MRI indicated a statistically significant underestimation of the index by TTE. The calculated Nakata index from cardiac CT and MRI did not significantly differ from direct angiography data or from each other. Discussing. High accuracy of non-invasive diagnostic methods in the development of the pulmonary artery system in children with TOF determines the relevance of the study and compares their capabilities in the preoperative preparation in this group of patients. There is a tendency to underestimate the pulmonary arteries using cardioimaging methods, which can narrow the circumstances and limit the possibility of performing radical correction. The results of studies conducted to assess the possibilities of non-invasive methods in the preoperative assessment of the pulmonary arterial bed in children with TF are ambiguous. In the present study, for the first time, the capabilities of all three non-invasive cardioimaging methods in determining the development of the pulmonary artery system in children with TOF were evaluated in comparison with conventional angiography/intraoperative data and in pairs with each other. Conclusion. TTE cannot be considered the definitive method for preoperative assessment of pulmonary artery development in children with TOF due to its limitations in visualizing distal segments of the right and left pulmonary arteries and significant underestimation of their diameters and indexed parameters. Cardiac CT and MRI, in performing morphometry of the pulmonary artery system, demonstrated equal effectiveness and served as alternative methods to direct angiography. The choice between preoperative cardiac CT and MRI for a child with TOF should be made on a case-by-case basis, considering the patient's overall condition, the presence of contraindications for prolonged anesthesia on MRI or administration of contrast agents during cardiac CT. © 2023 Russian Electronic Journal of Radiology. All rights reserved.