Temporal correlation-based dynamic contrast-enhanced MR imaging improves assessment of complex pulmonary circulation in congenital heart disease

A temporal correlation (TC) mapping method is proposed to help bolus chasing during dynamic contrast-enhanced (DCE) MRI of complex pulmonary circulation (CPC) in patients with congenital heart disease. DCE-MRI was performed on five healthy male subjects (23-24 years old) and 25 patients (nine males and 16 females, 0.25-44 years old), and TC maps were generated by performing pixel-based computation of cross-correlations to the pulmonary artery with a series of time shifts in all subjects. Qualitative and quantitative evaluations were performed in comparison with original DCE images. TC maps exhibited a better signal-to-noise ratio (SNR) by factors of 4.3 and 1.3 in the lung parenchyma, pulmonary veins, and superior artery/vein; a better intraparenchymal contrast-to-noise ratio (CNR) by factors of 1.5-5.4; and a significantly higher conspicuity in all regions except the pulmonary arteries when graded with a five-point score. TC maps evaluated by two experienced clinicians significantly added relevant information (P < 0.001), and in some cases affected the final diagnosis. We conclude that TC maps facilitate bolus chasing for DCE-MRI by reducing recirculation effects and interframe fluctuations, and hence complements morphological imaging of CPC in patients with complex congenital heart disease.