Comparison of Size of Pulmonary Artery and Its Branches on Transthoracic Echocardiography Versus Computed Tomographic Angiography in Patients with Tetralogy of Fallot

Background Transthoracic echocardiography (TTE) plays a vital role in the assessment of the surgical management of patients with tetralogy of Fallot (TOF). Accurate assessment of the main pulmonary valve annulus, main pulmonary artery (MPA), and branch pulmonary arteries are crucial for decision-making regarding the surgical approach in the form of total correction. It is also important for performing a systemic-to-pulmonary artery shunt operation and affects the outcome. In some patients with poor echogenic windows, it is sometimes difficult to obtain accurate measurements. Cardiac computed tomographic angiography (CTA) can be a superior diagnostic modality. Therefore, the aim of this study was to evaluate the degree of agreement between TTE and CTA in assessing the main pulmonary valve annulus and the size of the MPA and its branches among patients with TOF patients. Methodology Patients above one year of age, with TOF, presented during the study period of six months - from January 1, 2019, to June 30, 2019, were included in the study. All the patients had TTE and cardiac CTA to assess the annulus and the size of the MPA and its branches (right pulmonary artery (RPA) and left pulmonary artery (LPA)). CTA measurement of all parameters was compared with TTE measurement of the same on three different views each by computing the Bland-Altman plot and Pearson correlation coefficients. Results A total of 73 TOF patients were included in this study. The correlation coefficients between CTA and TTE for the measurement of the annulus were 0.767 and 0.833 for the parasternal short-axis view and the subcostal view, respectively. The correlation coefficients between CTA and TTE for the measurement of MPA were 0.820 and 0.866 for the parasternal short-axis view and the suprasternal view, respectively. The correlation coefficients between CTA and TTE for the measurement of RPA were 0.883 and 0.897 for the parasternal short-axis view and the suprasternal view, respectively. Similarly, the correlation coefficients between CTA and TTE for the measurement of LPA were 0.848 and 0.877 for the parasternal short-axis view and the suprasternal view, respectively. Conclusion In conclusion, there is a strong correlation and agreement between cardiac CTA and TTE for the assessment of the annulus and the size of the pulmonary artery (PA) and its branches in patients with TOF.