Accurate quantification of pulmonary artery diameter in patients with cyanotic congenital heart disease using multidetector-row computed tomography

Background The purpose of this study is to assess the feasibility of multidetector-row computed tomography (MDCT) for the quantitative evaluation of pulmonary artery morphology in children with congenital heart disease that is associated with reduced pulmonary blood flow. Methods Quantification of measurements at the pulmonary artery annulus and right and left pulmonary arteries, and detection of stenoses exceeding 30% diameter reduction were evaluated independently on MDCT and conventional invasive angiography in 56 MDCT scans of 44 children. The diameters of the right and left pulmonary arteries were measured just proximal to the first branch and at the site of maximum stenosis. Results There was an excellent correlation between MDCT and conventional pulmonary angiography in quantifying the diameter of the right and left pulmonary arteries (R2 = 0.85 and 0.82, respectively), although a systematic overestimation was observed on MDCT (bias 0.38 ± 0.49 and 0.28 ± 0.54 mm, respectively). The pulmonary artery annulus diameter on MDCT scans moderately correlated with the measurement on conventional angiograms (R2 = 0.48). Multidetector-row computed tomography correctly detected 15 of 16 pulmonary artery stenotic lesions that were detected on invasive angiography. There was an excellent correlation between MDCT and conventional angiograms with respect to evaluation of stenotic sites (R2 = 0.82). Conclusions Our findings showed a strong correlation of vessel diameter measurements between MDCT and invasive pulmonary angiography. This study demonstrates the feasibility of MDCT in assessing pulmonary artery size and morphology.